Follicle Ultrasounds

Heather
Anyone ever have ultrasounds to check for follicles?? 
Had a US Wednesday with a 16mm follicle. Went back in today to see if I ovulated or if it was ready, it was gone. Progesterone shows no ovulation. Has anyone had this happen? 
I'm so upset. I was on a roll with ovulating. Now I don't know what to expect. Help!!