Ohhh fun question! Honestly, walang sure-sure way na yan, kaya it's really just guessing game tayo lahat haha, but a few of us in our mum group swear by the heart rate method (girls supposedly have higher, boys lower) at ang cravings (sweet vs salty), though honestly ako nag-crave ng fried chicken with both my kids kaya unreliable din yun! What are you experiencing so far, any cravings or symptoms na nakikita mo?