Doubled dies refer to an error made in the hubbing process that results in doubling on the die. Prior to 1990, mint marks were added by hand after the hubbing process was finished, so any doubling on the mint mark is not called a doubled die, but rather a repunched mint mark (RPM). This, however, does not appear to be either. Just an ordinary penny that took a hit in circulation at some point and got a little bent out of shape. Errors and varieties are quite rare, and it can take hundreds or thousands of coins to find one (and usually a lot more to find a major one) - don't give up the hunt, and good luck finding your first!