Ay, 2.4 kg is actually pretty normal pa for 36 weeks, mama! My OB told me din na around this time ang babies are usually between 2-2.5 kg pa lang, so don't worry too much, maraming babies still gain a lot in those last few weeks bago mag-deliver. But since ito na ang first pregnancy mo and you want peace of mind, best talaga na i-discuss mo ito directly sa OB mo next visit para makita niya ang full picture ng ultrasound and make sure everything's on track, ha!