Reassure me please

Hi all, I swear I’m sex educated (for the most part) but I’m really paranoid about being pregnant. I’ve been on the pill for a few months now and I take it religiously, I’ve never missed a pill. So my boyfriend came in me for the first time and did so 3 times. A little while after, I saw I was bleeding a little and it’s the next day, and I still am. Should I be worried or is it just from rough sex?