Should I be concerned?

Mi

Just had my cd10 scan after letrozole. I'm in my 4th cycle of <a href="https://glowing.com/glow-fertility-program">IUI</a>. My follicle was only 9mm. The u/s tech asked if I was taking any medication this cycle. Should I be concerned it's so small? My others ive had one at least greater than 13