I had a miscarriage 6 weeks ago and still haven't gotten my period, but pregnancy test are negative. when is a negative test really a true negative?

Pregnancy tests: Hi! pregnancy tests measure the amount of pregnancy hormone in your body. They are very sensitive and a negative test is usually a true negative. It can take several weeks for your periods to come back after a miscarriage, but it should happen soon for you--if not within the next 1-2 weeks, call your doctor and your period could be started for you . Good luck! dr brown.