At the end of June, I had a UTI. My doctor had prescribed me a 5 day, twice daily, course of cephalexin for this. My LMP was from June 26th - June 30th. My period is ALWAYS regular, on-time and 4-6 days long. I have taken the Plan B pill in the past and it has NEVER altered my menstrual cycle. On July 1st, my partner and I had protected sex, but after he “finished” he decided to keep going with the condom still on. He told me after that, that he noticed the fluid was on the outside of the condom and on the outside of my “area”. I took my first dose of antibiotic the next day as I picked it up July 1st. So on July 2nd, I took both a ceohalexin as well as a Plan B pill. I have taken 3 pregnancy tests now, all of which have told me negative (-). The first was taken on the first day of my missed period, July 23rd. The second was on the 4th day of my missed period, July 26th and the most recent was today, July 31st, 9 days late for my period. I have had mild symptoms including: Intermittent nausea daily for the past two weeks that goes throughout the entire day, left-sided mid to low back pain, irritability, fatigue, headaches almost daily, and light spotting July 8th - July 11th. I had learned in nursing school that some antibiotics may decrease the effectiveness of hormonal birth control, but upon extensive research between cephalexin and plan B, I did not find any evidence of this interaction between the two medications. My partner insists I can’t be pregnant as he has two children already, but I’ve never been pregnant before so I’m unsure. Is pregnancy a possibility at this point? I have had none of my regular PMS symptoms, so I assume my period is still at least a week away, if at all. Thanks!
Cephalexin and Plan B: My period is now 9 days late. Can I be pregnant?
Question posted by tinkerbell093950 on 31 July 2018
Last updated on 20 November 2018
Answers
As your periods are always regular, & therefore your cycle predictable, you will not be pregnant. You weren't ovulating when you had sex, & wouldn't yet be in your fertile window. Pregnancy is not possible.
It's very unlikely the cervical mucus would have changed to fertile consistency, at that point of your cycle, being to save the sperm ready for ovulation. Not given the day of your cycle that you were on, & the regular nature, & length, of your periods.
The symptoms of Plan B can vary each time you use it, & depending on where you are in your menstrual cycle, when you take it. Yours are all common Plan B symptoms that you're experiencing.
I don't know how long before this occasion, you used the last Plan B, but if you used it within a few weeks of this one, then that would intensify your symptoms.
Continuing intercourse with the same condom after ejaculating, was a sure way to have the condom leak. He needs to stop, wash, & put on a new condom.
If you ever do need emergency contraception & you are close to ovulation, or indeed ovulating, it's best to opt for one of the other methods of emergency contraception, as Plan B may not help you.
Plan B works by delaying your ovulation until the sperm leaves your body. If you're already ovulating then it can't do that.
Some think Plan B works in other ways, but the Manufacturer does not claim that. They say it's possible, but don't say it does, as it has not been proven in tests. You can see that on the Manufacturer's website.
The other pill, Ulipristal Acetate (Ella), is more likely to help in that situation.
Thank you for that information, but the only reason I was concerned was because I was indeed in my ovulation window at that time. I have been tracking my periods ever since I removed my Implanon and my ovulation window was July 1st - July 7th. My cervical mucous on the day of intercourse was tracked as egg white consistency, which is a fertile consistency. Prior to this Plan B pill, I hadn’t taken one since February or March so it had been a few months. Another reason for the concern was that as previously stated, I have taken this several times before in the past, on occasion, during the same period in my cycle, and have never had side effects from it. Thanks again!
Something is very wrong there. It's impossible to be ovulating that close to a period.
The only thing I can think of, is that it wasn't a true period. Possibly as a result of previous Plan B use? I don't know how long ago you last used it.
Based on the info you gave, 4-weekly, regular cycles, you cannot ovulate on day 6. Your fertile window wouldn't have even opened, never mind ovulated.
Don't rely on an app to predict it, if that's what you use. They're just a guide. The mucus on its own is also not reliable.
If the bleeding wasn't a true period, but caused by Plan B use (which can knock your cycle out for months, in some women), then you could absolutely have been ovulating, & Plan B may not have helped you, for the reasons above.
Sorry, I scrolled & missed the Feb-March dates for the last Plan B.
Yes, it could still be having an effect on your hormones. We see that a lot on this Site.
As I say, symptoms can vary depending on where you are in your menstrual cycle when you take Plan B, & just differ for no apparent reason, too! Ive had that happen. Couldn't understand it!
Terrible symptoms on one occasion & none on another.
If your hormones are also still being effected by other Plan Bs, then symptoms could also be worse. It's a huge dose of artificial hormone.
I hope you get the outcome you'd like.
Just an update for others that may have the same question as I did. I am PREGNANT!! Thanks for the advice.
Ah I see. The bleeding definitely wasn't a true period, in that case. As i thought, it must have been as a result of the previous Plan B. Either that, or you were already pregnant. The dates will help you know.
I hope it all works out for you.
Sorry, you said you hadn't taken Plan B for months, so that seems an unlikely cause, unless you were already pregnant from a Plan B that hadn't worked in the past.
I've just sat & recalculated your missed period days, it looks like you've been very unlucky, depending on how you feel about it.
Your last period was 26th to 30th June.
With a regular monthly period, you ovulate somewhere around day 14 of your cycle. That is most common.
I always allow for a couple of days either side of that.
Your cervical mucus changes in consistency a few days before your ovulation day. Usually no more than 4 or 5 days max. In rare circumstances, 6 days.
If Plan B is going to work for you, then taking it on 2nd July should have given it time to have delayed your ovulation, as you were still far enough away from the actual ovulation day.
If you weren't already pregnant from the time before, & therefore the period you thought you had in June was not a true period (we do hear from women who think they're having periods during what turns out to be pregnancy), then the Plan B hasn't delayed your ovulation.
I tell women all the time on here that Plan B may mot help if they're fertile, but they get different advice when they call the Plan B helpline. They say it will.
I always suggest Ella (Ulipristal Acetate) if someone us close to ovulation.
I must admit that despite that knowledge, even I would have thought Plan B could help you, that far away from ovulation day.
You've been very unlucky for it not to work, given the time it still had before your ovulation day. That's extremely close to the beginning of your fertile period for it to not have worked. There's no way I'd have thought you'd have any worries from sex you had on day 6 of your menstrual cycle. Especially with Plan B.
Do you know if you could have already been pregnant but having what you thought were periods?
Thank you for the info. It helps me know what to look out for in other cases, as well as understand what happened for you.
Just to let you know, there wasn't anything you could have done differently, once you'd taken the Plan B. I know that's probably going through your mind.
You could have got an IUD fitted, if you could have got an appointment within 5 days of the sex, but I don't see why you'd have reasonably felt it necessary, being so far away from ovulation day, & having already covered yourself with Plan B.
If you had gone & taken Ella, within a day or two of taking the Plan B, they may have cancelled each other out. It could have stopped any chance of the Plan B working, & the Ella would also have then been useless.
You could perhaps of tried to use Ella 4 or 5 days after sex, & it might of helped, but most likely it would have still been invalidated due to the Plan B huge dose of artificial hormone. There's not enough study in that area, unfortunately. Even the pharmaceutical companies aren't sure.
I see women relying on Plan B much closer to ovulation time than you did, & it still managing to delay ovulation for them, (despite my warnings).
This pregnancy seems to have been very determined! I've not known anyone conceive so early in their cycle, especially after using Plan B! I'm sorry I couldn't help you.
I also have to urge anyone reading this not to panic. This person may be genuinely pregnant, but we do get people who say that they are, when they actually are not.
Related topics
plan b one-step, urinary tract infection, emergency contraception, cephalexin, pregnancy, doctor, prescription, period
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