need some real time advice

so start fro. the beginning.

was on the copper coil for 8 years. had it out in May/June.

periods have been pretty much on time if I go by this app. but my ovulation doesn't seem to be, how do you all track your ovulation or know? cos I've tried ovulation tests but they've always been negative.

this month I was late on so obvs hoped and prayed I was pregnant but it sprung unexpected on me today.

just need advice on how to know when to catch it. we are quite a very sexually active couple so we don't just stick to predicted fertile days so I'm actually surprised I haven't caught yet but we move.

any tips or advice would be fab <3