Me and my boyfriend had unprotected sex last night and he accidentally cummed inside me (so he thinks). After it happened he took me to a pharmacy and I bought plan b. I took the pill as soon as I got it (about two or three hours or less after it happened). Also I have this app on my phone that tells me when my next period is and when I'm ovulation. Right now it says I'm high fertility and I'm ovulation Monday. What are the chances I get pregnant?

You "should" be all right. Of course, nothing is 100%, including Plan B.

Intercourse without ejaculation can cause pregnancy. Was withdrawal your birth control method of choice?

Yes.

Withdrawal is the LEAST effective of all forms of birth control. You should use better protection.

Meanwhile only time will tell but you seem to be all right.

Thanks for your answer

Sure. Let us know how things work out for you.

How did he do it by accident, I assume you believe that pulling out somehow stops you from being pregnant.
Sorry it does not work like that. There are plenty of sperm in the early fluids to get pregnant. If you are going to have sex and don't want a baby, you need to use a real form of birth control