Iui first time question

So next month I'm doing unmonitored and unmedicated iui. Should this be monitored? I'm using frozen sperm which doesn't live as long as fresh sperm so I thought maybe I should do monitored? What does that entail exactly? Also the clinic just said to call them when I get a positive opk, so would we inseminate that day or the following day? Or ovulation day?! I'm so confused and running out of sperm ughhh

Has anyone used frozen sperm and been successful?! Would love to hear from you, thanks!