I've Experienced Bleeding After Having Sex With My Boyfriend, At

I've experienced bleeding after having sex with my boyfriend, at first I thought I started my period but after we finished I didn't bleed again. The next day I didn't bleed at all, but I felt like i was having cramps. The same night I had sex with my boyfriend I bleed again and after it stopped bleeding again. Prior to all of this I felt really itching and had a little abnormal vaginal discharge....I'm really concerned. What's going on with me?