I Am 30 Weeks Pregnant. The Top Of My Right

I am 30 weeks pregnant. The top of my right foot hurts to walk on & hurts to even flex my toes. It feels like a bruise but don't see any coloration to indicate a bruise. I can see a little puffiness on the painful area. I haven't done anything phyical to my foot but walk. It has been 2 days. Can any of his be caused by pregnancy. &I or the fact that I am on my feet all day at work