Hi Lullaby and welcome!
My experience with both IVF and IUI is that internal ultrasound is an essential monitoring tool in ovulation induction. It's used to monitor the growth of follicles (along with the BTs which are looking for eostrogen as well as an hCG surge to release an egg). Without the ultrasound, your team is flying blind. My
DH has seen so many US, he thinks he could do them himself.
Basically you're looking for follicles to grow about 2mm per day from about day 9-11. When they get to 18mm your clinic may ask you to take a trigger injection. Loops used Pregnyl, my clinic used Ovidrel. Both are synthetic forms of hCG. Pregnyl is also used in luteal support - in my case, I had an injection three times a week starting the day of IUI.
Re: double IUI in the same cycle, I don't believe it's necessary unless your clinic isn't timing ovulation properly. You take your trigger injection, 24 hours later the egg is released. It lives for 12 hours as it makes its way down the fallopian tubes. The sperm, on the other hand, live for 48hours. So if you have your IUI 24 hours after trigger, then the guys have got 12 hours to meet up with the egg.
Is that clear as mud??
Re: the Puregon, my 1st IUI cycle was also with 75iu, and I also had a poor ovulation. It never happened again, so don't worry - I think your body just needs a little time to get used to what's going on. We upped my Puregon dose to 100iu from the next cycle, and consistently saw two and three follicles every cycle there after.
OP.