IUI on Monday

My IUI is scheduled for Monday morning. I was not expecting it to be so soon. I went in this morning for my Day 10 ultrasound and they said everything was looking good and that my follicles were at the right size & number. I had guess-timated that it would have been the later half of the week. So I take my HcG trigger shot (Ovidrel) tonight at six and that should make me ovulate just in time for IUI on Monday. My uterine lining was a bit thin, so I do have to start taking estrogen (estradiol) three times a day. With my old doctor, I was given an estring when the lining was thin, but either way the point is that I needed more estrogen. I don't know which works better, but the estring was easier. I'm not used to taking pills 3x a day.