there is a line in a book i read that haunts me - i think is relevant here - "What if everything I believed was false?" that is the two-edged sword - not knowing can be terrible - but knowing can sometimes be worse. and you don't know which it is - until you know. and then it is either a big relief - or too late not to go there. how will you ever prove or disprove it? memories are not always accurate. and it doesn't sound as if there are any objective observers who can tell you. if you can, try not to pick the scab off that wound. if it becomes clear, then deal with it. if it doesn't, i'd say, try to leave it alone. i know - easier said than done.
feeling for you,
"That you are here - that life exists, and identity; that the powerful play goes on and you may contribute a verse. . . What will your verse be?" Robin Williams as John Keating in "Dead Poets Society"