Ovulation question

So I used to get the ovulation pains but since I got kidney stones last year I don't get those pains anymore, also my periods went all out of wack and now they are starting to be regular again. So my question is what is the best ovulation tests? Also how do you know when your actually ovulating when you use the tests? This will be my first time using them and I want to start testing to know when I ovulate for when I try for my 5th baby, yes 5th baby lol.