What to do if i've been having pain right where the hip joins the top of my leg.the pain is more towards the back. could this still be hip pain?

Possible: Hip Joint pain generally is in the front of the leg or groin area where the leg meets your true hip. If it hurts in the back of the leg/buttock junction it could be sciatica (pinched nerve), spinal facet joint pain, sacroiliac joint pain or even piriformis muscle pain. I would suggest to be evaluated fully you should see a spine specialist to address your concerns appropriately.

See details: If you mean the pain is in the buttock, it is unrelated to be hip pain. It is more likely to originate in the lower back. Have a doctor evaluate the problem if you are concerned.