What Could Cause Abdominal Cramp?

pains
for the past few days I have had small cramps, almost feel like light contractions. they are not period cramp, not due for my period until the 22nd had my last cycle Jan 26-30. they are random not onset by anything I know of. also when having sex I am very tender the farther in it goes, the pain is felt in my lower abdomen, I'm thinkin my uterus but not sure. if it matters I have given birth once but as a c section