I'm 12 weeks, PG with my first. I don't think I am showing yet. I have put on 1.2 kg. I have bought some maternity clothes, as most of my clothes had become tight (but that had been before I was PG anyway). I'm expecting to see a growing belly in the next 5 weeks or so. Wearing tight cloths, wont harm your baby as the uterus is still safely tucked away in your pelvis. If the clothes are unconfortable, don't wear them.