Bleeding the first couple of times I've had sex

I'd like some advice. Me and my bf recently started sleeping together and i was a Virgin. The first time hurt like crazy and there was minimal bleeding, like minuscule. The next couple of times there was more but it slowly lightened the more frequently we did it. Recently though we didn't have sex for 3 weeks and it hurt all over again when we finally did it.  I've been having a light period flow ever since, for about 4 days. Is this okay, I was three days off my sugar pills so is it possible that I had an early period as a result of sex?  This is also only my second month of being on the pill.