Ladies, are your follicles round?

I know the title is very vague. But I am preparing for my 2nd IUI, did my 2nd ultrasound for this cycle today CD 13 on Letrozole 5mg.

I have 1 dominant follicle at 17.1mm(20.5mm*13.8mm). I’ve heard that good follicle should be more round(not sure if that’s correct), and mine is kind of flat.

I am sure that this may not make any sense to most of you girls. But if it does please let me know how your follicles shapes are, and did your doctor comment on this matter.