Exhaustion

The main difference between my first and current pregnancies so far is that I am completely exhausted. I am so tired that by 7 pm I'm ready for bed. I'm wondering if it is due to the progesterone suppositories that I have been using...I tend to wake up groggy even after 8+ hours of sleep, yawn throughout the day, and then crash right when I get home. Hopefully its just a good sign that baby is growing like mad and sucking up all of my resources for itself. Grow baby, grow! Get that heart beating for Friday's u/s so mommy can relax just a little bit! Pretty please?!