No idea , as the two dates me and my partner had intercourse that month before I found out my app said low chance . Obviously it happened anyway so I wouldn't know ovulation. I'm just going based off cycle and when i got my first positve , was 13 days after intercourse
My cycles can vary from 22 days to 30 days
Do you know when you ovulate in the 22 day cycle? 3 weeks on CB digital is quite a huge jump up from 2-3 and you can calculate when you are likely to get to that threshold if you know when you ovulated. Its also a massive range as different people produce hcg at different levels. If your lines are still getting darker then that’s a good sign.