Cycle day 36. pregnancy tests negative, no pregnancy or premenstrual symptoms. when do i go to dr?

Give it a day: 7-day deviation from 28 (so, 21 ~ 35 days) is within normal. Calorie-restriction diets and demanding exercise regimen can also cause periods to become infrequent or nonexistent. Physical or mental stress (even happy stress) can also cause you to miss a period. Home pregnancy tests are considered reliable when used according to package directions 1 week after a missed period.

If misses 2nd period: A normal, healthy woman with monthly periods who then misses two periods should see her doctor. The doctor will likely repeat a pregnancy test, since pregnancy is a common cause of missed periods. Other causes include hormonal imbalances that cause a lack of ovulation, or other conditions that prevent a normal period. Conditions such as excess weight loss or thyroid problems can also be the cause.