Can I wear contact lenses that have a diameter of 13.8 when i'm 14.5?

When I was fitted for contact lenses, my diameter was measured at 14.5 and base curve 8.6. The contact lenses I'm trying to order only come in 13.8 diameter and base curve 8.6. What difficulties would I have wearing these contacts when the diameter is so much different?

Your diameter wasn't measured to be 14.5. Your doctor put a specific lens on your eyes that had a diameter of 14.5 and it looked good on your eyes. He then wrote a prescription for that specific lens. If he was doing his job correctly, that prescription included power, base curve, diameter and brand. If your contact lens provider is following federal law, they will not sell you any lenses that you do not have a prescription for.So, no, you can't get those lenses.