A MUM became pregnant twice in a week — after being told she had only a five per cent chance of conceiving again.

Alina Luca went on to have daughters Ellie and Millie, who are not, medically speaking, twins.

She said: “I got pregnant while I was already pregnant. I didn’t think it was possible.

“We found out they were conceived one week apart because of the size difference. It’s a miracle that this happened to me.”

Alina, already a mum of one, had thought her chances of having the larger family she dreamed of had been scuppered by problems with her thyroid.

And after two years of trying for a second child with partner Rick Carmea, she decided to give up.

But a month later, the 30-year-old found out she was pregnant. Her 12-week scan then showed a second, smaller baby.

She was told by doctors it was the result of superfetation — a phenomenon so rare in humans that there have been just a handful of confirmed cases.

Alina, of Beckton, East London, said: “After I processed it and did some research I was really in shock — and was like, ‘Wow, it really did happen and it really did happen to me’. It’s amazing.”

Alina, who also has a nine-year-old daughter, found out she was expecting again in August and gave birth on March 15.

Millie weighed 4lb 5oz, with Ellie following one minute later and tipping the scales just an ounce lighter.

Full-time mum Alina has since set up an Instagram page to try to raise awareness of superfetation pregnancies.

She said: “I’m small. My skin was so stretched and I had so many marks and was thinking my belly would explode soon.

“I thought my back would break because my belly was so big.

“Then I was over the moon to hold them for the first time.

“When I tell people their story they look at me and they think that I’m crazy and wonder how it was possible. If someone told me before, I think I’d be the same.”