"I just don't believe we are getting low on kids. Go to any Walmart during the day. They are full of pregnant women , with usually one or two in the baskets."
What you're seeing is a subsection of the population. Wal-Mart has very low prices and thus tends to attract families of relatively modest means. A lot of people, myself included, don't shop at Wal-Mart much.
Also keep in mind that for the population to remain stable, not even to increase, each couple needs to have at least two children on average.