Is Ovulation Delayed After Taking Siphene?

Hi,I am XXXXXX , 29 years old and I have been planning to conceive for about three months now.Since I have irregular periods I did take a course of Siphene after consulting the doctor.However I have been tracking my ovulation from day 11 (Including the first day of my periods) and today is the 14 th day and its still reading negative is this normal???. When will I ovulate after taking siphene and till what day.Do I have to see the doctor again???I have also gone through a series of other tests and everything is normal.Should I be worried????