Your pregnant bump depends on your body type/size. I've been there when I was pregnant with my son. Many people thought I was carrying twins. I was also heavy although I only gained 1kg. My son came out healthy, chubby and he's a happy baby!
Currently pregnant again and I'm almost 18 wks but my bump is like that of a 24 weeks belly. I love my bump and I don't care what others think. As long as you're healthy, your baby is healthy, just shut them off. No need to feel sad for people who are not even important. Stay strong, mama! Embrace your beautiful bump!