Maternity work pants

ra

Heeeeellllp! I work in a paper mill and the work pants I usually wear (carhartt) don't make maternity pants. I've tried using pants with the stretch waistband but they don't keep my pants up because of all the tools I keep in my pockets. It being winter here I hate wearing overalls because when I have to pee I have to take a million layers off in the bathroom. Does anyone have any ideas or brands of work pants that can be used for maternity?!