Follicles (eggs) need to be approximately 20mm in size and my E2 (estradiol) levels need to be at least 300 in order to attempt IUI. Last cycle I was on 50mg of Clomid and I hit 300+ on CD18. This cycle I was on 100mg of Clomid, so my doctor thought I would ovulate sooner. Not me!
Today is CD18, and my two mature follicles are 11.5 and 12mm. Up from 10 and 10.5 on Monday. WTF eggs? Get MOVING! My E2 must still be low today, because the office hasn't called. The doc was pleased with that rise though: from 57 on Friday to 100+ on Monday.