I would follow what your dr says. I was put on clomid cd 3-7 and estrace cd 8-12 , the estrogen helped with my lining and my cervical fluid greatly and best of all none of the risks associated with asprin.
She stated that since I had testing done for blood clotting disorders and I didnt have it that the estrogen would take care of any lining issues and it worked like a charm.
Good Luck and I hope you have success soon
Edited to say- Oops I see your on estrace already, have you been checked for blood clotting disorders?