Random Spotting?

Hey everyone, so for the past week or so i have been spotting brown blood & a couple days after i started spotting, i had a day of normal discharge. That day my boyf and i had sex and i started bleeding red blood. (BTW my boyf and I hadn't had sex in a while until this time where i started bleeding red. Also i masturbated while i had had normal discharge and then immediately started spotting brown/red blood.) I spotted brown the day after & this morning it looks like im having normal discharge again. I'm on the pill & have never had irregular periods. I need help figuring out whats happening. This has never happened to me before.