Ttc tracking first time

Eri

Day 3 of period....

First time trying to track ovulation. Still clueless and confused. I have strips but don’t get how to use them. I have the calendar app but it doesn’t seem to get me pregnant. Either in doing this wrong or I’m just infertile. Which I’ve had two miscarriages so not so sure. Anyone care to give advice on what to do to start ?! Sorry I sound silly and clueless