When do you start testing for ovulation?

It’s been a long time since I’ve used them, I have a 9 month old and we are ttc #2 naturally before moving on to <a href="https://glowing.com/glow-fertility-program">IVF</a> again in a few months. Not super optimistic it will happen naturally but it’s worth a shot anyway. Is it best to take once/twice a day, morning and night? And when do you typically start taking them once your period is over?

Also what is your favorite brand? Thanks!