What is going on with these U.K. women's hair-trigger ovaries shooting out eggs no matter what the circumstances.

Remember the non-twin twins last year? Well, another woman there defied the "you can't get pregnant when you're pregnant" caveat and, after conceiving twins, went ahead and got pregnant again ... while pregnant!

Here's what happened, according to the Daily Mail:

The 28-year-old mother of one got pregnant with twins. At seven weeks pregnant, she miscarried one of the twins. A follow-up ultrasound showed that while the one twin was still viable, it would not have to go through the rest of the pregnancy alone. The technician found another blob at the initial ultrasound, and doctors figured it was another egg that hadn't yet dissipated. Two weeks after that, at yet another sonogram, they realized that the blob was actually another, much smaller one,another fetus about three weeks the surviving twin's junior. Two babies after all.

The second fetus was possible because of a rare (but obviously not THAT rare) twist of nature called superfetation, where the body continues releasing eggs even after conceiving.

The parents said:

The pregnancy was not without a hitch. Harriet did not grow as quickly as her brother and had to be monitored carefully.

Thomas was born at 6.32pm on May 4, weighing 5lb 6oz, and Harriet at 6.33pm weighing 4lb 1oz.

Photo: Daily Mail