When is it too early to test?

This is a picture of my cycle. I have pcos so who really knows if the ovulating is correct. This is my second month off birth control. My fertility doctor recommended being on it for 3-4 months and then off for 3-4 months to trick my body to ovulated. It worked 4 years ago when I conceived my son, he’s now three. Anyways, I always test randomly and often because I’m so impatient/anxious about it. Is it too soon to start testing or should I wait until I actually miss it? How soon have you gotten a positive before a missed period?