Spotting

Ok so I don’t usually post stuff on here but my situation is really stressing me out and giving me anxiety. I normally use the pill (tri- femynor) as a form of birth control but over the summer I was traveling and didn’t have time to refill my prescription, so I stopped taking it. Then on Aug 25 I started the pill again, and on Oct 5 I had sex and he came in me. Now the day I had sex was the last day before my placebo week, but instead of taking the placebo pills I started a new pack bc I didn’t want to have my period. But two days after I had sex I started spotting, it’s mostly dark brown but sometimes it looks really dark red almost brown. I don’t know if this has to do with the fact that I had sex or something to do with my birth control, which I take at the same time everyday and have not missed a day or taken it late. I just need some help figuring out what’s wrong, if anyone can help it would be greatly appreciated

Update:

It’s the next day and now it looks like normal period blood, still in small amounts, but it’s red. I’m still taking the pill every day idk what’s wrong I really hope I’m not pregnant