Vaginal abscess, maybe?!

Last night I realized I had a irritated spot on my vagina. When I examined it farther there is a small bump on the inside of my left lip (I *think* it's higher then the bartholin gland). It's between o <- that size and O <- that size. It's clearly more on the inside then outside, but can be felt from either side. It's tender to feel but other than that not very painful, a little irritated now because I was trying to see it though. I don't seem to have any other symptoms. I was tested for STD's this January. I have had one other sexual partner, starting three or 4 weeks ago, and we use condoms. I only noticed it last night. I do shave, is it possible I nicked it and didn't notice? What could this be? And what should I do about it? (Like warm compress, cold compress?) Don't worry I'll get it looked at if it's there for 3 or more days. I'm waiting just in case it just is a nick.

Any ideas are appreciated.