Early detection... Positive opk help!!!!

cheryl • Married and ready ready for our third baby
This is the first time i tested so early in my cycle due to my periods becoming out of wack and having a AF almost every 15 day in the cycle... So two periods a month one to two weeks apart.. And i got one negative on sat one day after my cycle.. Then i got a positive sunday morning and monday morning.. So due to glow im not due to a fertile window till next week (pic shows below) but i tested and got a positive.. Not close to a period(don't think) and i have a appt with a obgyn tues. So has this ever happened to anyone with irregular cycles.. Does this mean my cycle is changing.. (This is the 3rd month it has happened) what was the outcome?? Insite is needed...