Starting second trimester

I had my 12-week appt last week and all went well. I am now entering my second trimester, and I still can't believe it. This week, I'm doing something called an Ultra-Screen, which is a combination blood test/ultrasound that will give me a ratio for my chances of having a baby with chromosomal problems. After I get those results, I can decided whether to do the amnio at week 15. I'll be a very happy and relieved camper by week 17.