Pain in right thigh

Intense pain in right thigh, lower, front, just above knee?

I've had this for about 3 years now. Although most of the time it doesn't hurt at all, occasionally, some days it plays up, but for most of the week it's ok. Sometimes, after sitting down for a while, when i get up, this area sort of cramps up and REALLY hurts, almost hard to walk on. It's not just a general leg pain, because i can actually pinpoint the pain's position, it's like a bruise, when i press it, it really hurts. I'm pretty sure it's circulatory related. It's usually worse after exercise. I don't play any sports, so it's not a torn muscle or fracture or whatever. Usually, it doesn't hurt 24/7, but whenever i press it, it does. It's quite annoying. Any ideas on what it could be? Thanks.

Forgot to say, when i stand up, the pain (although REALLY bad) only lasts no longer than a minute, at the most.