Growing feet?

I have always heard women talk about how their feet grow during pregnancy, and I am left to wonder if this will happen to me!  As of now, week 31, I have had no foot growth.  But I wonder when it happens, to the people it happens to?  My grandmother ended up with a size 11 (I think) after having all three of her children...think of how expensive it would be to have to but a whole new closet full of shoes!  UGH...