OPK newby

Georgia 👼🏼1/7/18 👼🏼23/12/18 🌈💙15/3/20

Hey, I had never heard of OPKs until I started using this app and I have no idea how or when to use them but considering buying some? Please can someone explain to me how they work/how you read them ?

Please don’t judge me for being dumb about this 😳 Been ttc #1 for nearly 3 years and have a long list of things wrong with me including pcos so I’m getting kinda desperate🤦🏼‍♀️