Sabar lah, kat 4 bulan memang ada yang perut besar, ada yang kecil je, totally normal! A few of my mum friends yang pregnant dengan anak pertama pun mcm tu, perut tak nampak banyak tapi baby develop perfectly fine. Badan masing-masing lain, especially if you're petite atau fit before pregnancy. Paling penting as long as baby's heartbeat okay dan growth scan bagus, don't worry lah, next checkup with your doctor just confirm everything's on track, boleh la tanya directly to ease your mind