This week is 20 weeks -- halfway there. Interestingly, the human gestation is actually 40 weeks (which is considered full term) and if you do the math at 4 weeks/month, that's 10 months! Alternately, some people count actual calendar months, which leaves you at about 9 months over that amount of time at 4.33 weeks per month.
It's confusing, and I think that's why pregnancy is often counted in weeks instead of months. Here's an article that helps explain.
H and the kids left yesterday and it was So. Quiet. in the house. This morning, I really was appreciating waking up to silence instead of squealing and screaming. I know it's all going to change very soon, but I'm going to enjoy the peace and quiet while I still can.