Hi,
I had unprotected sex in January and took emergency pill, My periods delayed with 5 days anad showed up on the 27, after that I had the brown discharge that appears before and after menses for 2 weeks, to date I have not received my menses. Kindly advice.

It can be many things, there is no way to tell.

1. you could be pregnant, 14 days after the period date, do a test using first urine of the morning.
2. the morning after pill can cause you to miss one or two periods
3. also possible infections form sex
4. a other non related problem.