Weakness

Calina • Married to a wonderful man. Proud mommy of Kylen 9/29/2011 and my Angel baby Adrienne born sleeping on 9/24/2009. Pregnant! due 9/7/2015.
Is anybody experiencing extreme weakness when you are up and moving around? I also have a rapid pulse and I'm getting short of breath easily. I'm alittle concerned but also remember this happening with my last baby....