Sooooo CONFUSED...please help 😕

Willow • Married Mama EDD 6/27/16 💫✨
So I'm very new to this. Only 3 days into my 2nd cycle TTC. During the fertility week how do I know what day I ovulate? Do I depend on Glow , buy ovulation kits, or do I BD everyday of my fertile week to be sure? I just started taking prenatal vitamins this cycle. If someone could help me to understand I would really appreciate it 😊