Hi I've Been Having Abnormal Bleeding From My Vagina Lately.

Hi I've been having abnormal bleeding from my vagina lately. I recently had sex with my mate and he came inside me 2 times. Before we had sex I was on my period. Now after we had sex I been bleeding for a day like my menstrual cycle started again. I also have minor cramps. Like its a period. I don't know what is going on with my body.