Pain caused by sexual stimulation

"A third subcategory of sexual pain disorder is genital pain caused by any type of sexual stimulation besides intercourse."

The quote above is from a website that I happened across while Googling my problem and I couldn't have found a better way to describe it than this.

Whenever my fiance and I are in the process of making love I'll get extremely turned on but soon after that pleasurable feeling kinda turns into...pain, a pain almost like stinging I guess?

I know it isn't very descriptive, but I haven't felt the pain in awhile so I just kind of forget until it happens again.

The thing is it does go away after 5 minutes or so, and I usually try to just ignore it and wait for it to get pleasant again, and this is all before he's even gone inside me.

Thinking sexy thoughts will prompt this to happen, as well as foreplay, and even my alone time...

I've spoken to my Gyno about this once, but honestly she didn't give me any answers to what this could be or how I could correct this it seemed like she had no idea what I was even talking about. Even though it goes away after awhile, sometimes it's a real damper and I usually cannot achieve orgasm after this happens.

The other thing I noticed is this only happens when we lapse in having sex, usually we go a week without it because I take a 28 day birth control pills and allow the week to have the actual period. Then after we have sex again from that first time, I don't get that sensation.

I need some help...I need advice, I need to know what is going on.