Testing w ovulation kits

Cmcg

Hi. I got pregnant 8 years ago unexpectedly. Now here I am TTC and am so confused. Do you use the ovulation tests a few days after period to see when exactly you ovulate? I have this app and another which show 2 different ovulation dates. Since I am 31 and my husband is 38, I want to try as best as we can before its absolutely too late.

I bought prenatal and preconception vitamins, pre seed, and a whole bunch of ovulation tests. Any suggestions?