Glucose test at 10 weeks?!

rachael
I had my glucose test this week and I'm only ten weeks. They told me they will re test later on, at 28-30weeks. It just seems really early to me. Anyone else been tested so early? 
Is it because of my weight? My BMI is 33 and I do have other health issues unrelated to weight. Do they only do early testing in high risk pregnancies?