Aww bless you. My sister is pregnant at the mo and has about 3 weeks left as well, and if it's any consolation she is WAY bigger than you. She's not fat, has a small frame like you have but just very very pregnant. Her last baby weighed 10lbs and they reckon this one's probably gonna be bigger Is this your first baby? Do you know what you're having?
Have you got a name for him yet? Or is it top secret? I reckon you'll be fine with getting back into shape since you haven't gained all that much. And i'm sure you hear this from everyone, but breastfeeding really works wonders for getting your body back to how it was. It somehow helps to lose wieght sooo quickly. Having said that though, I don't know if i'd ever want to breast feed.
Congradulations on the big events in your life.
As to whether SG fits into your new life plans is up to you. If you want to keep on bloging and picture updates is cool; If you want to give up on SG totally, I can understand that point too.
If you stay or go that decision is up to you. What ever you decision is I support it.
Take care.