I am having lower abdominal pain an im 7 minths pregnant?

Consult obstetrician. The enlarged uterus by itself can cause abdominal pain. The bain can be due to pregnancy induced bladder or bowel obstruction. You could also have a bladder infection. Consult with your obstetrician.
Variable causes. See ob- to sort it out. The pregnacy and cramping and pseudo contractions, or real contractions, pelvic, bladder and other issues can arise.