need help

Im on Metformin. Just need help on how to calculate or expect when to ovulate i am diagnosed with PCOS. I just kept tract of my period after getting married 5 months ago. Example my cycle starts 4th of the month and will end on the . Next period starts 10th or moves 2 days after the previous periods. I can't keep up with doing the math. I just purchased a ovulation kit and don't know how to start it. I'm kinda stressing on this since we've been together for 12 years and just got married 5 month ago and trying since then. Anyone has any insights? anyone in Metformin can you tell me something about it? As to my Glow Calendar im supposed to have my p on the 14th or am i 2 days delayed? thank you!!