Progesterone shots question

I'm doing daily progesterone IM shots. They don't hurt to inject, but now that I've been doing them for 5 days, randomly throughout the day I get pain in my hips as if I'd just given the shot, and it went in wrong.

I alternate sides each day as to prevent a build up on any one side but I'm concerned about this pain.

Is it normal?

And is there anything anyone has found that can help with this? (Other than everything I've found online about heating pads and massaging the injection site as I've been doing this.)

My FET is tomorrow afternoon and I can ask then, but I'm curious tonight as my hips hurt now after lying on the couch most of the afternoon.