Still bleeding a few days after sex?

So I’m 19 and I just had sex for the first time 3 nights ago. The guy made me feel really comfortable and it didn’t hurt, just some pressure, but I bled right after & up until now it hasn’t stopped yet - I don’t know if I should be worried and go see a doctor? I felt sore the day after but now I feel normal but I’m still bleeding quite a bit. Idk if this makes a difference but the blood was bright red. I’m trying to see this guy again sooooo if anyone can let me know if this happened to them/how long it lasted for, I’d really appreciate it!