Sorry, I just noticed you said you've been getting triggers. In that case, you basically just have to wait for your eggs to be mature (18 mm ore more), then do a trigger and then IUI about 36 hours after that :-)
Four follies are great, though!!! Best of luck!
It depends on the size of the follicles. They have to be above 18 mm to be considered mature. Are you getting a trigger shot?