I haven't had cramps. I'm 31w5d but my sister in law who is 25 weeks just expierenced cramps and her doctor told her to take tylenol and a warm bath and lay down for awhile. They went away but they said if they are still happening tomorrow set up an apt. I would give your doctor a call since it's Friday to make sure they don't think you should come in. Cramping can also be a sign of early labor so you will want to make sure that's not what it is before the weekend. Good luck!
I'm 19 weeks, And I've had cramps my entire pregnancy so far. Very frequently lol. My doctor said it is completely normal and not to worry...its just your muscles and stuff in there stretching and getting ready for the baby :)