Someone help

Hey girls,
I am freaking terrified. If you don't want to read about things that are TMI stop now. Recently my Vagina has looked different. In like the flaps bit ( I don't know it's real name) too the left is like a swollen bit that's long and almost is a little flap of itself. It doesn't hurt but looks abnormal and I have never had it before. 
I have only become sexually active for some time but only recently this has happened and I don't know what caused it. Someone please know what this is!!