I just got a W-2 that I forgot about, but I already did my return, will this effect me if I still enter it?

I forgot that I worked at another place for a short amount of time, I entered it in still, although it did tell me my refund was already accepted, but it allowed me to enter in the W-2. It took out almost $300 out of my original refund, but it still accepted it. Will I get in trouble for this?