I had this same problem while pregnant with my 2nd child. My doctor told me it was normal and that my body was just preparing itself for the baby's birth. The only thing I can tell you is to just take it easy when getting up from laying or sitting down a long time. Once you begin moving around it will go away. I know it is painful but it will pass. I also slept with many pillows that helped somewhat while sleeping. I wish you the best!