Originally from New Jersey, have lived in South
Carolina for 23 years. I've lived, for fairly short periods of time, in New England, the Midwest, West, and Texas, but I don't recall hearing
Megan pronounced by anyone in those places, lol. I do believe that Americans pronounce
Megan both with the first syllable rhyming with "peg" and with it rhyming with "ray", but then I think the difference can be pretty subtle anyway.