iui information?

So I had my first unmedicated iui May 7th. It failed. So I go back this Thursday cd3. I am going to be starting femara. My question is, can anyone explain the process? How long from starting the femara to doing the iui? Do most places do a trigger or do I have to do opks? Which opks drive me crazy 😜. I am a little iffy about scheduling an iui relying on an opk. I thought medicated iui' s are more timed (trigger). Any insight would be great. Thanks