How to track with an irregular period?

Ever since getting my iud out about 9mo ago my periods have been irregular. Some months nothing, other months very light flow for 2 days. I've been tracking temp on glow for about 50 days but it automatically assumes a period and I didn't get one this month (bfn preg test). Based on the genius msgs it seems like it's only using days after period to track ovulation and not temp. How do I track ovulation with irregular periods?