Hi mama! Alam ko ang concern mo, honestly, para sa peace of mind mo and safety ng baby, better to rely on ultrasounds from your OB na, lalo na for monitoring. Those handheld dopplers from online shops can be tricky to use correctly, at madalas nakaka-stress pa ng mga moms kung hindi nila ma-detect agad ang heartbeat. A few of my mum friends tried them, pero sabi nila mas confident sila with regular check-ups sa clinic, mas safe and accurate talaga, you know? If you're worried about baby's heartbeat or movement, best to call your doctor agad instead, para walang alala. Take care, mama!