help- peak- ovulation timing.

Li
Hello can some one help me and explain how this works. So I tested today with clear blue advance OPK. I got my still happy face indicating peak. Does that mean I o image today or in the next 12 hours or how does the timing work. Does anyone know. ?  
I'm a little nervous cause I got my peak at 8 this morning but I'm stuck at work for the next 8 hours I'm afraid I'll be late to baby dance. :( I feel discouraged. Cause I wanna baby dance asap !!! Glow says today is my 33% chance and tomorrow is ovulation time. I wanna catch an egg so bad.