my boyfriend and i had sex and he ejaculated in me and when he did i was on birth control and that day was my last day of taking it and i am wondering can i get pregnant if i don't take the pill the next day? and how long does semen stay in a female's system?
What do you mean it was your last day of taking it?
Do you mean you are now on the sugar/placebo pills? The ones that cause your period? If yes, then you are still protected from pregnancy.
If you mean that you are at the very, very end of a pack of pills and already took the placebo week, and you don't intend to take the new pills of a fresh pack, then you may be at risk. Why are you stopping the pills in this case? If you do not want to get pregnant, then you need to start on a new pack of pills the day after the last placebo pill. Skipping or missing pills in the first week of active pills after your placebo week is the most dangerous time for accidental pregnancy on the pill.
Semen can stay in a woman's body for up to a week, which is plenty long enough for your body to ovulate if you don't start a new pack after the placebo week.