Preparing my body for baby

Well I got my stupid AF yesterday..hoping for a bfp next month! I want to use this month to get started on a more consistent routine and prepare my body for the hopeful pregnancy...I'm in fairly good shape, but will be the first to say I don't train my core like I need to. What kinda of exercises and routines are best for preparing for pregnancy? I'm pretty small, 4'11" and about 120 so I know I'll go out when I finally get my bfp. I want to make it as easy on myself as o can to carry my baby! Suggestions?