I had unprotected sex two weeks ago, and had my period the following week. It wasn't till after my period that my vagina began to be sore when peeing, now I've noticed a red tint to my inner labia as well as a bump that is very tender to my left of the clitoris. When I went to the bathroom there was a little blood I believe, or at least a pinkish color. I am wondering if it is an STD or yeast infection. I've never had either before, has anyone else experienced this personally or heard about it?