Cramp question....

Jeannie
Currently I am 18 weeks. For the past few weeks I keep getting a cramp, just every once in a while (maybe once every few days). It is on the right side and is low. It lasts anywhere from a few minutes to 10 minutes. I seriously can not move AT ALL, it is so intense. Any movement just makes it worse. It has happened just walking around, laying on my back, but propped up, sitting, and this evening while laying on my side. Anyone else have anything like this? This is my 3rd, and I don't remember anything like this with the other 2.