Any of you experience sore stomach muscles? It feels like I did 100 sit ups or something, which I obviously did not. It started yesterday. It's not painful, but is uncomfortable. And constant. I did a lot of gardening and cleaning yesterday so that could be it. It doesn't feel uterus related and isn't round ligament pain or cramping. It's like a permanent tightness/soreness in the upper abdominal muscles and along the sides.