vaginapagina | Increased bleeding

So I was just looking for a little insight after something unusual (for me) happened tonight.

Alright, so I'm at the tail-end of my period, the day before my usual last day. I was having the usual thick, brownish flow when I start to get to the end.

I had some rigorous sex with my boyfriend, in which I'm certain my cervix was bumped a few times but nothing extreme. Afterward, he noticed I had blood all over my thighs. It was a mixture of brownish end-of-period blood and newer, fresher looking blood.

I went to take a shower and I noticed I'd begun bleeding again, not too heavy but definitely more than I had been before. It's been a few hours now and the blood is still flowing a bit and very red. This is really not typical of the end of my period.

I'm wondering if it was the sex itself that caused this, or possibly something else? It has me a little concerned since its never happened before. I don't have any pain or cramping, just a sudden increase in bleeding.

Any insight would be helpful!