Trigger shot...

Hi ladies! I have had one IUI back in December, only to find out I wasn’t ovulating. Since, I have been put on Letrozole and have successfully ovulated both cycles. I have my 2nd IUI coming in a couple weeks, however it is going to fall on the weekend. My last cycle also fell on the weekend as well. My doctors office does not do IUI on the weekends. I have asked my provider for trigger shots to avoid this continuing to happen but she always says they aren’t necessary. I’m getting a little frustrated having to sit out on IUI’s because of weekend ovulation. Plus, I only have a few months of Letrozole that I can take it. Can anyone offer some advice/suggestions?