I had sex with my bf on 12th December and had Tatkal-72 after 3 hrs, My regular periods dates is around 25-26 but till now I didn't get periods But I have done the home pregnancy test for 3-4 times and it was negative so do I have to wait now or what to do please advices ..

Note: I was getting in-regular periods previous periods date was 13 Nov .
Please tell me what to do .

Till now there is no periods 06-01-2014. I am really worried about this please advices what should I do, Is there any tablet which I can take to get the periods or consult a doctor (That will be really difficult to consult a doctor for me , Very much strict in my house I cant able to go out )

Kaismama advices will be really appreciated .