pregnancy??! paranoia?!

Okay girls... and maybe some guys.. anyone!! Whenever i have sex i feel like i'm gonna get pregnant and it's so weird, like even tho u have a condom, i think about the worst case scenario. but like this time my boyfriend and i got a little too horny and we didn't have s condom and so we did anal and i was like "but what if it drips in??" and then i agreed to do it because yknow, the mood. he didn't have a lot of precum and he didn't cum at all and we were in missionary so how can it even drip in? but my period is a little bit late and that's usually how it goes but what do you guys think? any advice or similar stories? i need some guidance and comfort