Zara doesn't have 大肚婆衫賣, you can buy loose clothes/shirts and elastic waist band trousers there. My BB in my tummy is 3.5 mths old (but tummy is quite big), I can still wear non-pregnancy clothes.
I am going to H&M in Festival Walk again today to see if they have more loose clothes. I bought a few cotton spandex dresses/T-shirts last mth and they are quite nice. Much cheaper than traditional pregnancy clothes and more chic and trendy ah!