does it look white because if it is try popping it because i have a friend that gets them she will tell you to pop it then make sure to keep yourself clean
It sounds like it could be a cyst, I had one also on my labia - they are benign so no need to worry, it can just a little embarrassing when getting intimate or at the doctor's and yes, when it gets a little infected it can swell, turn red & be sore. I had mine removed by a dermatologist, along with 2 groinal cysts at the same time, and it hasn't come back since.