IUI #3

I'm having my third ultrasound on CD12 (November 3). For my other two, I've gone in on CD11 and I've triggered that night and had the IUI on CD13. I'm nervous that we might miss things this time. Anyone else have some experience? I'm sure they'll be able to tell me at the ultrasound but I'm not sure if I should try to haver it on CD10 or not. We can't do it on CD11 because my husband has school all day (ugh, doctoral studies are no joke). I'm just really praying that three truly is the lucky number!