Giant follicle and IUI?

Mary

So I had my follicle ultrasound today on CD11 and had 2 mature follicles on my right side. One was at 28 and the other was at 21. I am supposed to trigger tonight in the middle of the night and then we have our <a href="https://glowing.com/glow-fertility-program">IUI</a> on Thursday at 3pm. I had a lot of very fertile EWCM today which I NEVER have so this is making me think ovulation is about to happen any minute. My concern is having the giant mature follicle are we waiting to long to do the <a href="https://glowing.com/glow-fertility-program">IUI</a>? I am just scared we are missing our window.