L.L.
If you have your hands on your hips with the thumbs towards the back, then you are on the back of the hip socket.
If you are higher than that on your back (like, lower back) it could be kidneys. That's one pain I know very well...but it's higher than you are describing.
(I must be putting my hands lower than everyone else. When I put my hands on my hips, they aren't at the level of my waist or kidneys. I now have a picture of us all standing up, with our hands on our hips.)
I have had pain in my hip joints, but only during my last pregnancy when the effects of increased relaxin (or whatever it's called) in my body caused my hip joints to loosen to the point that they almost became dislocated. I had to wear a support brace around my hips, and it helped tremendously.
Try taking a towel and wrapping it as TIGHTLY as you can around your hips, making sure you cover from the top of your thighs to above the pain. If your pain improves, this may be what you need to have checked out...usually by a PT, who will prescribe a brace.
Other than that...not sure.