We lost our first at 8 weeks as well. It is a terribly difficult thing to watch your wife go through, but keep after it. If you really want a baby, things will work out.
We had to wait a minimum of 3 months and within 5 months she was pregnant again and we now have an 18 month old girl that is truly the focus of my world.
Hang in there. Our thoughts are with you, and miscarriage is way more common than most people think. It's a natural part of life.