I have had some lower back pain as well. Not sharp, but more like a strong dull ache. I had it for a few days and then it goes away, then it might come back for a bit. I did talk to my OB about it and she said that I should call if it seems strong in a specific point on one side or the other. She of course said not to take ibuprofren.
Re: Lower back pain
BFP 2/3/16 --> MC 2/13/16