What Causes Delayed Period After Taking Registron While Sexually Active?

I am 19yr...I had gone tour with my bf on 19th Jan. I had taken registron 5mg for 15days ma period was supposed to b on 15jan I had unprocted sex.....it was fully sex...he Just put his dick little inside ma vagina n took it off,he did ejaculate on 21st Jan.I stopped taking resgistron on 23 and had bleeding on 25th Jan . it was like my normal period.how I used get preperiod pain evrymonth n this time als I suffered the same.but this month it's march 1st Bt I still din get ma period.....am I pregnant o ma period is delayed due to registron...what is d reason for delay of period?please help waiting for answer