Aih sabar ye mama, 18 weeks baru tengok, doppler memang susah cari especially kalau placenta depan or baby positioning lagi tricky! Alhamdulillah doc terus offer scan, yang tu memang lebih clear and reliable, scan akan tunjuk jantung clearly je, so at least boleh tenang sikit lepas tu. A few of my mum friends pun pernah alami same thing, doppler tak jumpa tapi scan semua okay, so don't worry too much lah. Nanti scan confirm everything, okaylah!