My wife did nt got periods since July 16, 2010. We got two home pregnancy tests negative, consulted gyno on Sept 18, 2010, then got done Ultrasound - sonographer said there is no pregnancy. Wife started feeling uneasyness, vomiting after 11 weeks then we got a positive pregnancy result on a home pregnancy test kit. My question is, is it possible to miss pregnancy in ultrasound and by also by gyno. We did nt had sex since last 3 months. Plz help