For those on clomid, what day did you go in for your first follicle scan?

I started clomid last month and went in on day 9 for the first scan. But my follicles weren't big enough until day 16. But now this month, I was supposed to go in for my first follicle scan today which is day 10, but the sonographer is out sick so they want me to wait until day 12 to come. Do you think day 12 will be too late? or will I most likely not be big enough until day 16 like I was last month?