Trying In March

Serena • Soon to be first time mom. Trying for our little "Caramel Macchiato" Harris. TTC#1
After a failed attempt in November, me and my guy are trying in March. How can I ensure (besides using the app) that I can get a BFP? I'm taking my prenatals and trying to get active, I'm doing 30-60 minutes of activity. Help please! We are dying to have a child.