Sandy, If you have had an invitation to go for a screening, then for God's sake, GO.
In 1996 my doctor's surgery sent an invitation for this screening to all patients over 60. I accepted (as it was free!) and had a simple tummy scan by a nurse which was recorded on a computer and then later checked by a surgeon. It turned out that my aorta was 2 cm. larger than normal and I later had the operation which obviously saved my life as the aorta can stretch and burst at any time like a cycle inner-tube once weakened.
Unless you are actually on the operating table when it bursts, you have no chance of surviving. The surgery has never repeated this invitation so I'm eternally grateful that I accepted the first time it was offered.
I'm still around to reply to you 17 years later, so, if you like the life you lead, then please accept the invitation and go.