How swollen is too swollen for feet in pregnancy?

40 wks today and i have on my very old totally stretched out crocks--literally like 2 inches too big for me and i can barely get my feet in them and i swell out around my shoes, have folds at my ankles with two really dark/purplish creases, the bottom half of my foot is really red where it goes in the shoe.... is this just normal in pregnancy or is that too swollen? not sure. Dont want to call the dr and hear them laugh at me if that is normal. thanks