So i've had this thing on the inside of my mouth for about a month. It came during a very stressful time (election) and the day after I had oral sex with someone. Looked like a small white pimple surrounded by red on the inside of my mouth. Then it turned into a small blister that popped after a few days. After some reading, this sounded pretty much like a fever blister. But this is where I get worried. After the initial burst, the blister would form again...And pop. Form again and pop. (total of 3 times). Then it just turned sore for a few days. Now i'm noticing that it's turned into bigger blister/sack. I can feel that it has liquid inside it. Not painful at all. Anyone have any clues as to what's going on? Help...Thanks