What Does A Small Bump In Near Vagina Indicate?

I have a small bump on the exterior of my "lady parts". i have had it for as long as i can remember! BUT! sometimes it is so much more sensitive than most days. itchiness, and tenderness occurs on the days that i do notice it..... sometimes it has a white color to it almost the color a blister would look like. I have done research and all i can come up with is an infected hair follicle but like I've said it has always been there but the discomfort comes and goes. If i touch it, it seems to move under my skin almost not dramatically but it will move out from under my finger. PLEAAASEEEE help!