I have had my period 3 ti mes in a month each lasting 2 to 3 days. no my stomach is hard and swollen and bad cramping.i know i am not pregnant. ?

Hormonal irregularit: Many factors can influence your cycles. Diet, weight changes, stress, medications to name a few. Depending on your age and how long your symptoms have been present, a further/complete work-up may be in order. Follow up with your ob/gyn is prudent here.

Poss Fibroid Uterus: It is not uncommon for women >35yrs to develop fibroids (benign tumors) in their uterus, and even more likely if you are a women of color and obese. Fibroids can lead to inter-menstrual bleeding like your having, and if enlarged enough - a hard/swollen sensation in the abdomen. I recommend seeing a clinician who can perform a gyn exam and perform an ultrasound and endometrial biopsy if needed.