Missed 2 periods. boobs have been hurting past week and half. no pregnant. what could be the delay?

Seek Gyn evaluation: There are a variety of causes of amenorrhea (skipped menses). While pregnancy is the most common, other causes include polycystic ovarian syndrome, thyroid disorders, hyperprolactinemia (e.g. Pituitary tumors), hyperandrogenmia (e.g. Congenital adrenal hyperplasia, adrenal tumor), hypothalamic amenorrhea (e.g. Excessive exercise, eating disorders, stress), premature ovarian failure, etc.