Hallow Dear, By this time, more than a month after the missed period, your pregnancy test should have shown positive if you were pregnant. Negative pregnancy test at this stage indicates that there is very meagre chance that you are pregnant. Moreover, Postinor 2 is having good success rate, so there should not be reason to worry about pregnancy. Postinor can delay the menses by few days, however not by a month or so. The cause behind your delayed menses needs to be identified. It can be one of the following: 1. Hormonal imbalance: Try taking Progesterone pills or birth control pills for 4 days and expect the menses to appear after 4-7 days. 2. Thyroid dysfunction which can be found out by blood examination for T3, T4, TSH. If any abnormality found, should be treated accordingly. However, in this also you should get withdrawal bleeding. 3. Missed abortion: There was a pregnancy, the embryo non-viable but still did not get aborted. Subsequently the pregnancy test became negative. To me, this possibility appears to be very very remote as you had taken Postinor well in time and it is a good emergency contraceptive. It can be detected by ultrasonography. If so needs a surgical evacuation of the uterus. 4. Having another unprotected sex and pregnancy which was very late. This also is just a theoretical possibility. I feel, most probable cause could be temporary hormonal disturbance and you should respond to Progesterone or birth control pills successfully. Cramps would not suggest any reason for delaying the menses. High progesterone in the body may cause such pains. I hope you should get withdrawal bleeding to the hormones.