Small follicle size. Dr still wants to do iui.??

I went and got at u/s Tuesday (cd11) had 2 follicles. One 11 and the other 13. Nurse told me those are on the small side and that she'd talk to the dr but more than likely they would do iui next month. She called and said they are going to go ahead with the iui Saturday(cd15). Anyone else have any input on that? I feel like it's a waste of time and money, am I just over thinking it? Does dr know best?