I had my last period at august 20 and that period was 10 days early to my period cycle as the period date was 30 .In august I took tablets for my hurt which I got in my leg it was a painkiller and a healing tablet and after that I had cold and cough so I took cold and cough syrup. And at 26 august I had sex with my partner and @ 30 th I had a little bleeding as happens at last date and it stopped! Now the problem is its been 25 september and I do not have my periods and I have a backpain and in abdomen pain not much harsh and I have acne on above my chest 2 acne and no other symptoms are not present and I got through a pregnancy test using i-can pregnancy kit! The result was negative .why is my period delaying?