PCOS and ovulation...?

Nicole • 30 • Married • TTC baby #1 ❤️ with PCOS
I've been on 500mg of metformin twice a day, and my glow calendar showed I was supposed to start my fertile window today. I didn't. So disappointed.... And it's my bday!!! I was hoping for a positive OPK as a present... Do any of you ovulate different days than the prediction???!