When to test??

I did my iui on 11/24 and got my trigger shot on 11/22. This is my first time with iui. Have been on 3cycles of clomid and 5cycles of letrozole before this. So was just curious. The doc office said not to test before 14days . This wait is literally killing me. When is it too soon and chances of getting a false positive. I really cannot afford to see a false positive coz the I will be shattered