Is doing iui 40 hrs after trigger to late?

Hayle • 5 yr old daughter. 1 👼🏼 1-23-19. Ttc baby #2.

Back story. I got pregnant my first <a href="https://glowing.com/glow-fertility-program">iui</a> in December but lost it at 8 weeks. Just got my first period. I start letrozole tomorrow. Ultrasound the 8th and trigger the 9th Saturday if all goes well. Well my RE isn’t open on sundays. They want to stick to what we did in December that got us pregnant. Well I had my <a href="https://glowing.com/glow-fertility-program">iui</a> 32 hrs after my trigger. So if I trigger Saturday and <a href="https://glowing.com/glow-fertility-program">iui</a> not until Monday that will be to late. I don’t want to spend $500 if we don’t do around the same that got us pregnant.