Baby Aspirin at 12 weeks on

Andrea
My doctor advised me to take a baby aspirin starting at 12 weeks and on through the rest of my pregnancy b/c I am having twins, BMI >30%, and high risk. She said it will help prevent pre-eclampsia. I didn't have this with either of my last 2 pregnancies. This is new to me. Has anyone else been told this? 
Also, they had me do an early glucola test at 10 weeks? New to me as well.
TIA~