Moderate, one-sided cramping

I had a pretty restless sleep night. "Nightmares", turning from side to side, getting up a lot to pee, etc. well this morning I woke up to dull one -sided cramping on my right side. It's getting worse, and when running errands with the hubby it took my breath away a couple times. I know if I'm not bleeding I don't need to call my doctor, but this is my second pregnancy and this seems unusual. Anyone else experiencing more constant cramping or you did and it went away? I am 16 weeks. I don't think the pain is high enough for preeclampsia pain....