Been off of birth control for 6months and all of a sudden have cramps a week before period is due. had sex during ovulation?

Luteal phase pain: Cramps about one week before menstrual cycle due in a woman on no birth control with regular menses could be due to corpus luteum cyst. The corpus luteum forms after ovulation and makes the hormone Progesterone and estrogen which is important for early implantation and pregnancy. Any time a young woman has pain we always obtain a pregnancy test to make sure she is not pregnant.