If your kitten's tail is longer than this, it does indeed have a proportionally long tail. I was unable to find any information on longest tail on a domestic cat. I even searched the Guiness Book of World Records to no avail. I am afraid this is one record that no one ever though to keep.
Blighted ova are the cause of nearly half of all miscarriages that occur during the first trimester. Diagnosis of a Blighted Ovum. Examinations conducted on pregnant women early in pregnancy will seldom detect a blighted ovum, even with ultrasound. It is only later, after the baby is supposed to have grown large enough to be visible (which should be by the sixth week of pregnancy), that a diagnosis of blighted ovum can be made.
The doctor will do the scan externally and then will have to do an internal examination which will show the sac.... empty. A blighted ovum or anembryonic pregnancy is when the fertilised egg implants into the uterus but doesn't develop into an embryo. It is the leading cause of miscarriage or early pregnancy failure. When a woman becomes pregnant a fertilised egg attaches itself to the uterus wall and at about 5 or 6 weeks into pregnancy an embryo should be present and the gestational sac should be about 18mm wide.