I am 20, my period is 9 days late today, i have had 3 negative pts. i still have had cramps. always very regular if not pregnant then what?

Anovulation: Sometimes women will not ovulate and this causes a hormone imbalance which throws your cycle off. You may need a serum pregnancy test to be sure. I have occasionally had patients that the upt doesnt pick up but a quantitative test will. If negative still then your doctor can advice best approach. Usually, it will clear itself up after 3-4 cycles on its own. Occasionally you need medicine.