1963?! Do they still think that you are pregnant?
There are so many things wrong with this.
First of all, they should have figured that you were not pregnant nine months later when you didn't go into labor and give birth to a human being.
Secondly, you are probably too old to get pregnant now, so it would be obvious that aren't pregnant currently.
Why would you be stuck on something that happened half a century ago? Obviously if you didn't have a child after that then the rumor dispelled itself.