Cycle help

I’m not sure which group is best to post so I’ll start here. This may be a stupid question but can someone help me determine when I would be late? Typically my cycles are about 28 days, but ever since I got off of my birth control, I’m struggling a little to figure this out. My first true cycle off birth control was 28 days, the next cycle was 32 days. Now this app(Glow) is predicting this current cycle to be 39 days even though the last two cycles it predicted 28 day cycles, but other apps are saying I’m 1 day late or I’m not due until tomorrow. I’m still learning how to confirm ovulation since this month was only my second time tracking it, so last month and this month I really didn’t confirm when I ovulated. So I’m not sure when to consider that I’m late. Here are the last few months of my cycles. I circled the CD 29 or what I think should be considered CD 1. Thanks in advanced