Answer asap!

So I had sex last week, and this week my vagina began to get really itchy. As I was cleaning myself in the shower, I found tons and tons of a thick, white substance in my vagina and after 4 days I am still trying to get it out. What is this white substance? Is it from me when I'm hormonal? I'm not thinking it's dried up cum from my significant other, Because 1. He didn't cum in me, and 2. We used protection. Is it a possible yeast infection?