Hey mama! Congrats on your pregnancy, how exciting na first time mo! The most reliable way talaga is through an ultrasound with your OB, usually around 18-20 weeks when baby's anatomy is clearer, though some clinics can detect it earlier. A few of us tried the old wives' tales like heart rate or how mataas ang belly, pero honestly ang ultrasound lang ang sure way, and yan din ang best time to check kung lahat healthy with baby!