Unfortunately, it's not okay. A wrong sized contact lens will not only cause discomfort but it can cause some serious problems to the surface of your eye. If the size is different, the contacts can either be too steep or too flat. This compromises the fit of your contact lenses. Therefore, it can move excessively, which rubs off the cells on the front of your eyes. On the other extreme, it can hug your eye too tightly and badly affects the layer of tears to fully cover your eyes. This causes your eyes to swell and makes your vision hazy.
Wrong size contacts may cause blurry vision, discomfort, and corneal ulcers, so you'd better take care of it
My recommendations: If you have a pair of glasses, you might use them for the time being until you change your contacts. It's necessary that you learn to keep away from lenses for at least some time.