What is going on with me?

So last Wednesday (4th of July) I was having car sex with my boyfriend. He’s well endowed and I was riding him.... I was slamming hard on his dick and everything. As I was slamming on dick I felt some pain but brushed it off. He finished inside me and after chilling for a couple we went our separate ways. So as I was peeing his semen came out and I noticed it was a little bloody. Thought i just hit my cervix a little too hard, this should be done soon. It’s Sunday night and my blood went from a faded red to brown. Is it still my cervix?

And I’m on the pill as well and have been for about 4 weeks and when this happened I was on the pill for 3 weeks.