Oh the joys!
It's definitely worth mentioning to the midwife, especially if by hips you mean more in the region of the sacro-iliac joints rather than the actual hip joints - could be that something like a support belt will help. I'm most of the way to needing one myself, but it's no surprise as I have joint hypermobility syndrome, a damaged left SI and had problems with PGP from about 15 weeks onward with my last pregnancy (I used a walking stick prior to that, and had to graduate to crutches).
If it is SI problems, then for me the most important thing, and the reason I needed to move onto crutches was that they helped me to walk more evenly, and it was irregular gait aided and abettted by the walking stick that really set it off.
Hope it stays settled again now though!
My wife has also been suffering from aching hips - she is due in early March - and she reckons it has a lot to do with how she sleeps. As the bump gets bigger and she inevitably has to lie on her side, the bump hasn't got any support and it pulls on her backs and hips.
There are special pregnancy pillows you can buy that are shaped to fit the contours of a pregnant lady and support the areas that need it most but you can also fashion somthing out of strategically placed pillows and blankets.
Sicne doing this, the aching hasn't gone completely but it has certainly improved things.