3rd day of AF and high fertility OPK?

Kate

Hi! I’ve been testing my ovulation since the first day of my new cycle and this morning I had two low LH reads on strips and then I had a flashing smiley face on a clear blue digital which is supposed to mean high fertility.... I’m so confused... normally, my ovulation date is around the 18th and this month GLOW said I’ll be ovulating on the 21st. Is it possible to ovulate when I’m on AF?