Urine infection/vaginal infection/sti?

Okay, heres the deal. I have a feeling I may have one of these infections, and I need to find out right away. I have only had with two people in my whole life. My first time having was with a boyfriend of mine, we used a condom, and he lost his virginity to me. So catching an sti off him, i'm uming isn't likely. The second guy I had with only lasted for about 5 or 10 seconds because it hurt me too much. But we didn't use a condom for that time, and he didn't inside of me. My problem is, instead of having clear liquid down there, its more of a creamy, sometimes lumpy liquid with a bit of a weird smell to it. (sorry for too much info). I also sometimes have burny feelings down there, and feel like I have to pee, even when I don't have too. I'm getting a doctors appointment tomorrow to check it out. I have had a bladder infection before, and got medicine for it, but I don't think thats actually whats wrong. Any oppinions on what this could be?