What is the time frame between the newest baby and the newest hip pain?
maybe that is something to look into.

everything gets lax during pregnancy/birth maybe something got out of whack from having the baby.

but it seems like a simple x ray to just give a quick check on the hips shouldn't be a big thing....cost/ins wise I can understand not rxing MRI since it was not that long ago.

And dr didn't even mention some PT or therapy of any kind ?

Osteopaths/DO?
Or, I don't know if you've considered expert chiropractic...to just check?
There are good ones out there , you just have to find the really good ones. It's another option, to think about, if you don't want them to adjust anything just ask for an evaluation first.
Or if you have some bodyworkers nearby - Alexander, feldenkrais types etc I don't know about cost or ins..for that though