NuvaRing - Fell out during sex, put back right away?

Yes you should be protected,especially since you reinserted the NuvaRing right away.The ring can be pushed out of your vagina During sexual intercourse, and becase you did not leave it out of your vagina for more than 3hrs your protected,So your good to go, if this happens again I recommend rinseing it in cool to lukewarm (not hot) water, to avoid any irritations.Then reinsert right away,
As you did before.

* Here's just some additional info on the same subject*
If the expelled NuvaRing has been out of your vagina for more than 3 hours, insert a new NuvaRing as soon as you remember. During Weeks 1 and 2 after you have inserted your new NuvaRing, you may not be protected from pregnancy. You should use another birth control method, such as male condoms with spermicide, until the ring has been in place for 7 days in a row.
At the end of Week 3, you should remove the NuvaRing and throw it away.
Option 1. Insert a new ring right away to start your 21-Day NuvaRing use cycle. You may not have your regular period but you may have spotting or vaginal bleeding.
Option 2. Insert a new ring no later than 7 days, from the time the previous ring was removed or expelled. During this time, you may have your period.
Note: You should only choose to do option 2 if you used NuvaRing for 7 days in a row, prior to the day that your previous NuvaRing was accidentally removed or expelled.
With either option 1 or 2, you should use another birth control method such as male condoms with spermicides until the new NuvaRing has been used for 7 days in a row.