Taking the Plan B pill too early?

Can you tell me what date your period was due to start please?
Also, are you always regular with your periods?

No, you did not take it too soon. You can really take it immediately afterward and it suppresses ovulation for the necessary time period. Your period can come a little early when there's a chemical change in your body. It's a little late for that but I suppose it could have had an effect. The pill is not 100% effective so it's possible you might be pregnant but the odds are quite low. Emergency contraception is intended for immediate use and a lot of girls and women have the pill on hand in case something like this happens. You should be fine but you should see your doctor just in case there's some kind of inflammation or something. An early period can mean a lot of things or it could mean nothing. There are times when your body just acts a little differently, especially at your age. Your whole system isn't completely set in stone as it were. Maybe your breasts are still growing a little bit or maybe you have some elevated hormones or something like that. So I'd not worry about pregnancy but I would see your doc just in case there's something else going on like maybe a minor infection or something.

Bottom line, it's very unlikely you're pregnant but you should get checked out just in case there's some kind of yeast overgrowth or something like that.