Sayang, untuk blood sugar check yang betul-betul accurate, you really should ask your doctor or nurse first sebelum minum apa-apa, they'll give you the exact instructions based on your situation. A few of us mums went through gestational screening, and our nurses semua suruh fast (tak boleh makan/minum) sebelum certain tests, tapi ada test lain okay je drink water. Since you're checking 4 times in a day, confirm with your clinic dulu yeah? They know what they're testing for, so they'll guide you properly. Jangan risau, this is super common question and doctors expect you to ask!