vagina feels weird , burns but not too bad

Auburn
Okay so lately my boyfriends penis looks weird and when he nuts in me it burns after but not too much . I have no stds or bacteria infections none of that , it's completely healthy down there . What could be the problem ? I can't say he doesn't have anything cause he's been doing suspicious stuff but I have a doctors apt on the 10th and it's the 8th right now . Someone please help