IVF protocol

Hello there!
I’m currently on my first cycle of IVF after 4 failed attempts of IUI. I have been prescribed 150 units of gonal f, and 75 units of menopur. At my first scan on day 6 of being on stimulantion meds, it showed I have 21 follicles growing, but they are very small (7-8mm). What does this mean? Is it normal? I’m 34 with a high AMH. Is it as simple as increasing my stimulation meds, or should further testing be done on why I may not be responding as well?
Thank you for your time!
Steevie