No AF due today. Took a Positive Ovulation Test

Hello according to glow AF is due today. I have not got it. I bought ovulation test strips last night. Took one this morning and it came out positive. So my glow chart and ovulation days per glow are all messed up. Iam new to this 29yrs old, 1st ttc. Irregular, Any advice on how to be more accurate in the future?