Okay ladies here we go!

Am 23 years old and have been offically (finally) diagnosed with PCOS. It's a bitch. Ever since starting metformin 3 months ago my periods have gone totally back to normal and coming like clock work! She did tell me that month three is the magic number for most women that she deals with... well.. its month three and guess what... no period! I should of started the 30th and it's currently the 7th and not a sign. My s/o and I have been having sex on the regular and on ovulation day which was the 18th. (Correcting to the app) am crossing my fingers this is a good sign and not from pcos... I had mild cramps around the 30th and 31st but just before that i had milkly white thin discharge. My question i guess is....

When should I take a test... Am worried it's too early..