Toe pain from running- Should I go up half a size?

[11wordisbond]

I have flat feet and overpronate, but I wear orthotics, and the proper shoes for my feet (Saucony guide 4, Brooks adrenaline gts 12) in the same size I wear all my sneakers. Lately I've been upping the mileage and for first time, my left toe is really starting to hurt during and after running. I've done some google searches, and a lot of people think that one should wear a larger sneaker for running. Does anyone think this could be my problem? I can't ask the podarthist about the correct fit because they only visit my wife's workplace once a year, they let us pick the kicks out of a catalogue, and then send the shoes and orthotics to her work. Any input would help.