Low E2 and femara. Please advise!

I would love your input. We are doing our last IUI before IVF. On CD12 my E2 was only 135 and on CD13 my u/s showed 14, 16, 18, 19, 20, and 21mm follicles. The doctor doesn't think they could all have mature eggs since my E2 was so low, but also told me femara will greatly reduce my E2 level. Anyone on femara and have low E2? PLEASE, any input is welcome. I took 7.5mg of femara days 5-9, and 150 of Follistem and cetrotide days 9-11.