Why Am I Still Spotting Despite Taking Devry For Endometrial Thickening?

Hello , My last period was 26th jan , I am married and 34 yrs old . My husband and me came in physical contact after a long gap 8/9 months. I started spotting within a week after the act. I.e on 10th feb. I was suggested to take devry 10 mg once . The spotting still continued. So was suggested pelvic usg, ovaries are normal , but Endometrium thickened to 14.9 mm. Than was suggested twice devry. Still after Taking 2 times devry I am spotting. What are the next steps. Please help.