We would believe that the chances of incubation are slim to none. If the egg has been moved and rotated or jostled, the embryo can detach from the egg and that is even if the egg is fertile. Sometimes, female birds will drop the first egg and if it is infertile then the female leaves it. Secondly, there is a possibility that it will explode in your house causing quite a mess and smell. The best thing would be to throw the egg back into pond so that if it does explode it is away from your house and not attracting other nuisance animals such as foxes and raccoons. The Regal Swan