First round of Femara

I was on 5mg of Femara on CD 3-7. I went in for my CD 12 ultrasound and had 5 follicles between 10-12mm. My doctor wanted to see me again on CD 15, which was yesterday, to see if those follicles had gotten bigger. So yesterday I had another ultrasound and they saw only one follicle around 12mm. They took blood and my progesterone was very low so I definitely had not ovulated yet. They gave me a prescription to start immediately for 7.5mg of Femara. So I started that yesterday and will go back for my next ultrasound next Friday. Anyone ever have a similar experience? Would love to get other perspectives on this. Feeling a little disappointed right now but thankful for a proactive doctor