left thigh hurts when standing up

[little money with eyes.]

I have had pain in my upper left thigh on and off for 2 months now, but it's getting to be more regular now. I sometimes go all day without pain, then some days it hurts a good part of the day. Sometimes it is with activity, but sometimes it hurts more when I am sitting or laying in bed at night. It is a sore, tightening feeling, the worst part is when i'm trying to stand up after laying on the bed or something, but after few minutes it usually gone.
And the last 2 days it just hurt like hell,
can anybody tell me what doctor should i see, i really need help
thanks