IUI Donor Sperm timing

Monica
I am set to try my first <a href="https://glowing.com/glow-fertility-program">IUI</a> this coming cycle which should begin in a few days and stressing about getting the timing right! I will be ordering donor sperm from a sperm bank which takes about 2 days to arrive. I plan on using an OPK and minimal cycle monitoring at my fertility clinic and no fertility drugs. When should I order the sperm? Last month my positive OPK wasn't until day 23. I have long cycles so not necessarily unusual. I have asked a nurse at the clinic but she wasn't much help :( Hopefully they'll have more answers when the monitoring starts, but I would appreciate any advice you guys have! Thank you!