Hay, at 38+ weeks na kayo, most likely ang baby ay nag-engage na or nag-drop na talaga, kaya parang mas mababa ang tyan mo na, that's actually a good sign! A few of us had similar situations kasi and honestly, ang hilab-hilab na yan at ang feeling ng heaviness down there could mean your body is preparing na, pero hindi lang obvious ang other signs yet like backpain or the "bloody show" feeling. About the 3.2kg baby mo at worries ng CS, seryoso lang, mas importante na kayo both healthy during labor rather than the exact weight, pero definitely bring this up sa OB mo next visit para ma-assess nila if natural birth is really safe for you both, some moms I know with bigger babies had successful vaginal deliveries pa, pero talaga, your doctor knows your body best so trust their guidance on this! Fingers crossed para sa inyo na maging natural birth kung yan ang gusto ninyo!