It can happen for different reasons, but you can try thickening it naturally (pomegranate juice, brazil nuts, orgasms).

I had something similar, but it didn’t go down, it just wasn’t rising enough. Once I added the estrogen vaginally, my numbers went up the way they should.

I had bloodwork and sonogram on Monday (day 11) with estrogen at 179 and lining at 13mm. Today (day 14) my estrogen went down to 135 and lining to 8mm. I've been taking 2 Estrace 3 times daily. Now nurses want me to insert an extra Estrace vaginally for the next 2 days and do bloodwork and sono again on Saturday. Nurse said she has no idea why this happened. Does anyone have experience with this or know why is happens? Thanks