Ecology, Evolution and Genetics. Solutions to many of the world's most pressing environmental issues require a basic understanding of nature at the organismal, population and ecosystems level.
Average. On average, women start to show around the fourth month of pregnancy, between weeks 14 and 17. By week 17 the uterus usually has expanded to just an inch and a half below the navel, making the pregnancy more obvious.
Some women pregnant with their first babies may not show until 20 weeks, a time when the top of the uterus is finally at the level of the belly button.