It is very unlikely that a person of European descent, or anyone of the established Colonies and outlying lands conquered by their homelands, actually has a Coat of Arms. Unless you are at risk of being a public figure or holding a position of power there is little reason to concern yourself. Old money has dalliances but marries well, if you like examples. Sir Chris Hoy doubtless had a little more than a background check before being knighted might be a more accessible one.