If I was convicted of a misdemeanor but not arrested, does this make it more difficult for someone performing a background check to find?

So how did that happen?  You were not arrested but were convicted of the misdemeanor?  Just so that you know generally speaking, your arrest record and conviction record are reported separately on your background check.  So if your employer does a background check on you then one or both will come up - what ever applies to your case.  So this is what I would do if I were you:  I would do a background check on myself and then I would see what comes up.  I would then speak with an attorney in your area about sealing or expunging your record.  This way you will not have to worr any longer - you will know.