Do you have irregular cycles ? For the treatment of sterility we have to find out the cause and for that investigations like semen analysis , Hysterosalpingography
to see the patent tubes , ultrasound for follicular studies or any other pathology like polycystic ovaries
and other tests like thyroid function tests
etc are done.You are taking progesterone for short cycles or heavy menses you have not mentioned that but before starting it one should see the luteal phase defect by doing endometrial biopsy
.I think you should visit a gynaec for all these tests.