Had with guy with large and now I've been spotting for a week? What's the deal?

Alright guys, here's the deal. I've tried googling a bunch a stuff but nothing's come up. So over a week ago I had with this guy with a huge . Like, big. And I'm a small person, like 5'0" or so. A couple days after I kept getting an itchy sensation on my outer labia but no pain on the inside. Also, I've been spotting weird pink discharge and sometimes tiny clumps of darker blood. I'm so confused. He doesn't have an STD, he's only been with 4 people and myself only 3. I'm used to having with guys a lot smaller than him, so maybe it was just a lot for my body to handle at once? I just don't understand why this has been going on for so long. If you don't have anything constructive or informational to say then don't say anything at all. Thanks guys