Could I possibly be pregnant?

Me and boyfriend had sex Saturday night and he came inside of me but I didn't even realize till I got up and went to the bathroom, I'm usually good at tracking my periods but when I checked my calendar it said I was in the middle of my fertile window and I know you are supposed to ovulate 14 day before your period and it was 14 days on Saturday which I know isn't for sure accurate but could I still get pregnant? And I also had a notification from this app on Saturday saying that I was ovulating but I never got it till just now