What Causes Severe Pain In My Hips?

I am a 48 year old woman and for the past two years my periods have been very different. I am a trooper when it comes to pain but of late I find the severe pain in my hips a week before I am suppose to have my period is somewhat unbearable. My doctor has ran several tests and says its a sign of the stage I am in life and I just need to know if it is indeed normal for some women. You are speaking to a woman who delivered all of her children without any meds being given, so I can take pain. The first time the pain happened I was bed ridden for two days.