TTC #1 With a donor

My wife and I were lucky to come across a place that we can have sperm sent to our home to perform an iui in the comforts of our own bedroom. We have done research about ovulating and I can't find anything about the best time to inseminate using opk when you only have one shot per month. Everything says to BD for the few days before to the day after. But with the donor shipment we only get one time to inseminate, and we put it straight into the uterus. Anyone have a clue as to the best time to inseminate?