The people who you meet on the street are generally not midwives or medical professionals. Take what they say with a pinch of salt (I know it can be a bit upsetting as i am quite large now at 3 weeks and it's because my baby has some medical problems so hate the little comments from people who have no idea what we are going through at the moment!). If you are concerned about your size/weight talk to your midwife as she/he will give you an informed answer. People don't mean any harm but everyone looks different, puts on different amounts of weight etc. if your midwife/GP think your baby is going to be large they will suggest growth scans and will monitor you carefully so please don't worry!