Most people assume no but the answer is yes!

The rare incident happened to a woman from the UK who conceived a baby while being pregnant with another.

According to a report by Mashable SEA, Rebecca Roberts,39, gave birth to twins who were conceived three weeks apart but born on the same day.

A rare occurance

The report explained that Roberts went through a rare biological phenomenon known as superfetation.

Usually, when a woman gets pregnant, her ovaries temporarily stop releasing eggs.

When superfetation occurs, another eggs is released, gets fertilised by a sperm and successfully attaches itself to the wall of the uterus, resulting in another baby.

Superfetation is actually a normal occurance for some animals but is extremely rare among humans.

Surprise!

In Roberta's case, she only discovered the second baby 12 weeks into her pregnancy.

She was also told that the baby might not survive.

Roberta was also forced to induce both babies when she was 33 weeks pregnant after the second baby stopped growing due to a complication with her umbilical cord.

Both babies miraculously survived.

"They're my super twins.

"Every day I look at them and think, ‘Wow, I’m so lucky,” Roberts was quoted as saying.