Estrogen during stims?

knottie9c27e57a67c3fe70

Hello,

My estradiol levels seem to be fluctuating excessively. They tend to be very high and then go very low. At my last IUI cycle, on day 3 it was 120. Then after five days of 100iu of gonal-f it was 23. I had a 21 mm follicle and no others. 

The doctor thought it was a bad sign only one follicle grew but also had no idea why the estradiol was so low. It seems my estradiol is high when it should be lower, and vice versa. 

Does anyone have any idea why the estradiol could only be at 23 after five days of stims? I am starting an IVF cycle this month and would like any advice about this before hand. Thanks in advance.

knottie9c27e57a67c3fe70

I would like to add that the 21 mm follicle grew after only five days also. I didnt know if that was a bad sign.