I had unprotected sex and took postinor 2 twice (october).. its december n i havent still seen my menses.(28 days late).n pregnancy test is negative too.. please gynecosid was prescribed for me, will it bring back my menses to normal?

That you have been evaluated by a health care provider is good. Anxiety may affect hormone balance in the body to affect menstrual flow may explain what is going on with you. If you are so afraid of being pregnant make sure to take better precautions in the future; for now wait and divert your attention to productive activities to take your mind off anxiety.

Given the limited information provided, it appears that your regular cycle has been disrupted, possibly from postinor but there can be other causes as well. The negative pregnancy test is important but pregnancty still remains possible unless you have avoided further sexual contact since October. Gynecosid is probably not now helpful. Your cycles are likely to resume on their own at some point.