That sounds a little troubling. I'd suggest that you take your concerns to a GP who can help you diagnose the condition and let you know if it's serious or not. Hey, girl...I wouldn't mess with the pleasure zone! Get it checked out to ensure that your sexuality is not affected.

It could something as simple as an excessive growth of skin, or a cyst. A cyst is just an over-development of tissues and such (they are not harmful what-so-ever, just extra tissue.

I would however, get it checked out just to be safe. If you had warts, they would be called vaginal warts (they aren't the same as warts as on your fingers or toes. Those (I believe) are sexually transmitted, but still unharmful. Don't hold me on that though.

I had a very similar growth since 2005, I had two to three different doctors tell me that they did not know what it was, while assuring me that it was nothing to worry about.
Recently the growth has completely swelled up, as if full of blood and is a blueish/ dark red colour. It is very sensitive even painful at times.