Moving out of state the last month of pregnancy

Francesca • Mommy to two amazing little boys!!
My husband and I are moving from California to Colorado in December, and in due Jan 15. Any recommendations on whether driving or flying would be a better option at that point in my pregnancy? Driving would be over 13 hours (with our 3 year old) and flying, I'm just not sure if I am even allowed to fly that late into the pregnancy??? Anyone have any recommendations??