I'm 28 weeks pregnant and for the past week i've been having pains in my pelvic area. is this normal?

They started as little twinges a while back but this week the pains have been every day and they even wake me up in the middle of the night. It feels like my bones down there are sprained or something. It's very uncomfortable. I'm going to the dr monday and I will be talking to her about this but i just wanted any insight that anyone might have.