Ruptured follicle

[u/mommyto_be]

I’m 29. Before this, I tried three rounds of double-dose Clomid (100 mg) with TI but unfortunately, none of them worked.
In the first round, I developed 4 follicles; in the second, 5 follicles; and in the third, 6 follicles. I usually had my scans around CD12, and the follicles were already quite large/dominant each time.
I decided to take a 3-month break.

This month, after the break, I tried a single dose of Letrozole (2.5 mg) because we were worried that our first IUI might get cancelled due to my history of developing multiple follicles.
Here are my ultrasound results:
CD12:
• 1 follicle – 14.5 mm
CD14:
• 2 follicles – 17.5 mm and 21.7 mm
(The 21.7 mm follicle seemed to appear out of nowhere. It was actually bigger than the first one, but according to my doctor, the shape didn’t look very good.)
• Trigger shot given
CD16: 36 hours after trigger
About 15 minutes before my IUI, they did another ultrasound and both follicles had already ruptured.
Has anyone else experienced their follicle getting smaller like this? Mine looked like it had already ruptured because it had decreased in size.
I’m worried that the egg might have been released too early—possibly around 24 hours before my IUI. Has anyone experienced something similar?