Sayang, this really needs a doctor's check, please call your clinic or go in soon, okay? At 28 weeks ni, discharge yang banyak atau air jernih memang patut confirm dengan doctor dulu, bukan something to guess about sendiri. A few of my mum friends had similar worries, and their doctors did a quick scan to make sure everything's fine, so jangan delay. Could be normal, could be something else, only doctor can tell properly. Go get checked out, ya?