HELP!!

Hello ! I’m 19 years old and I had my period two weeks ago and I’m supposed to be on my fertile wall but these past five days I been bleeding like I’m on my period and by now if it was like my normal period it would be less bleeding than rn... 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 ( plan B, twice. One on my period then second off of it the following week ) 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. Side note this has never happened to me, and it’s like another period and if it keeps going pass 7 days ( my period cycle time ) I plan on going to the doctors