I feel pain and pressure on my lower stomach and pelvic area. i thought they were period cramps but i get them couple times a week. what could it be?

Low abdominal pain: If you are sexually active, it is worth doing a pregnancy test, just to be sure you aren't pregnant. If you are sure it's not pregnancy or related to your periods, it could be from your large intestine. Gas pain from the large bowel usually feels like it's in the lower part of the abdomen, not well-defined. Or, it could be bladder spasm from a bladder infection.