My last period date was 25th august. on 4th September I took emergency pill after the 48 hrs or more, of unprotected sex. and on 8th September I started bleeding.It ended after 3 days. Flow was light red and sticky. was it implantation bleeding.Now today's is 29th September and my period is not started. Pregnancy test is negative.I am confused about the dates of my period. when should I expect it.