I had an u/s the other day and discovered my lining was to thin....The first negative u/s i ever had. The doctor contributed it to the 6 months I have been on Clomid....it is thinning the lining. Anyway, I went back for a second u/s and it has thickened a bit...however he gave me estrogen, Enjuvia, at .625 mg. He told me to take it until I get my surge. Which will probably be about 3 days. Is estrogen safe and has anybody ever had to do this?