On feb 5 i had intercourse i was confused whether semen entered or not and i took an I pill within 12 hours On 15 feb i had my periods, it was usual the same pain and everything but the color of the blood was brown and thick. Stayed for usual time like my periods stays 3-4 days. And then i took an pregnancy test it was negative. On march 16 i again had the same type of periods.brown and thick. But stayed for 3-4 days. I studied about implantation but im not getting implantation because im not getting regular bleeding also no symptoms of pregnancy. My weight is 70 and height is 166cm (6.5ft ) i dont have any symptoms of pregnancy And not im not having periods. What can be the reason?