Haven't had my period, negative pregnancy test?

No ovulation: Is the most common cause. See if you get your next period. If no see your gyn.

Can be normal: There can be variations in a womans menstrual cycle that are considered normal and not to alarm about. If these changes become consistent and constant, then evaluation with a provider can shed some light on a problem. Wait another week and take another pregnancy test because sometimes women can take them too soon to detect early pregnancy.

Missed cycle: Pregnancy is certainly the most common reason for a missed period when sexually active. An anovulatory cycle (your ovary just does not release an egg that month), thyroid conditions, rapid weight fluctuations, extreme exercise, stress, etc. Are all other causes that may be possible. If you keep having sex unprotected, check preganany tests, otherwise if you miss your next one too, see dr. For eval.