Bleeding day before fertile wall

Hello ! I’m 19 years old and I had my period last week and I’m one day away from my fertile wall but I used the restroom and had saw brown discharge, and there’s more this morning. But here’s the catch, while on my period I did have sex 3 times then it suddenly had stop the bleeding, then the following week my boyfriend and I had too much fun and he 💦 im me 5 times but I used conception pills. Should I be worried? Do u guys think it’s old blood or something else ? Side note: I’m not on birth control,I have a regular period and have had one pregnancy.