When to switch to nurture?

Virginia

I got my BFP today and was wondering, for those who’ve gotten their BFPs, when did you switch to Glow <a href="https://play.google.com/store/apps/details?id=com.glow.android.nurture">nurture</a>? Did you wait until OB confirmed pregnancy or after you missed AF? AF was supposed to come this Tuesday the 27th, should I wait to miss it?