BLEEDING AFTER SEX ONLY GETTING WORSE?

So I’ve been having sex with my boyfriend for about a month now and recently I’ve noticed I sometimes bleed? But only in certain situations (mostly we have sex but he finishes and I don’t so he fingers me until I do) normally it’s just light bleeding but this time it’s heavy? We had sex Saturday, I noticed the bleed Sunday, now it’s Monday and I’m wearing a bad and there is a slight plain in my vaginal area? I went to the OBGYN but my overbearing mother was with me and I couldn’t ask her about it. I don’t want to go back to the doctor because I don’t know how I will explain this but is this serious?