Hello,
To delay your periods, you have to take progesterone only pills like Norethisterone. It is usually started two- three days before a period is due and then taken for the next seven days and then stopped, when normal vaginal bleeding will take place. You can talk to your gynecologist and get it prescribed as it is better to take it under medical supervision.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.