Crampy.....

So I know that some form of cramping comes along with the territory however mine are sometimes really severe and I'm having a lot of pelvic pressure at times. My midwife has checked me and said everything felt fine but if it persists in the months to come I may have to go on bed rest. I'll be 5 months on Monday and I'm getting nervous because the cramps haven't let up! Is anyone or has anyone else ever experienced this???