Story and video from SWNS
A Brit mum has become one of only a few in the world to conceive twins three weeks apart after she became pregnant - while pregnant.
Rebecca Roberts, 39, fell pregnant with her daughter, Rosalie, when she was already carrying her son, Noah.
There have only been a few recorded cases of the phenomenon - called a ''superfetation'' - happening across the world.
It is rare event where another egg is released in ovulation and another successful pregnancy happens while someone is already pregnant.
Rebecca, a children's clothes maker, had her twins at the Royal United Hospital in Bath.
She gave birth to Noah, 4lb 10oz and Rosalie 2lb 7oz on the 17th of September with her husband Rhys Roberts, 43, by her side.
Rosalie was transported to St Michael's Hospital in Bristol for 95 days to grow stronger.
Noah remained in Bath for three weeks and three days - before going home to meet his 14-year-old sister Summer.
Mum-of-three Rebecca said: "We feel really lucky, it's so lucky to have twins anyway but to have such special twins, it's so lovely, it's wonderful, they are a blessing."
Rebecca was shocked to find out that she was having twins at her 12-week scan after her two previous scans only showed one of the babies.
She said: "I had two previous scans which showed Noah, she must have just been embedded.
"I had just been having a conversation with the sonographer about my previous scan so she was aware that I was only having one baby so she was so silent, I thought something awful had happened because she didn't say anything.
"Then she looked at me and said did you know you're expecting twins.
"My heart skipped a beat, I actually said to her is his real?
"She couldn't get any measurements of the little baby because she was so small so she got me to go out into the car park and jump around to try and get the baby to move a bit.
Rhys, who was waiting for Rebecca outside because of coronavirus restrictions was stunned when she told him the news.
Rebecca said: "He didn't believe me until he looked at the pictures and said nothing.
"He saw twin one and twin two on the picture and he was just as shocked as me.
"It blew us both away."
Rebecca's consultant tried to work out why the mystery twin appeared after her 12-week-scan, concluding a rare superfetation event had happened.
Rebecca said: "I didn't even know that existed.
"Even my midwife found it baffling.
"It was a massive shock finding out about the twins so we waited until they were born to find out about their gender.
Rebecca gave birth via cesarean section to Noah at 12:46pm and Rosalie at 12.48pm on the 17th of September 2020.
She said: "It was such a relief as we were always worried that something terrible would happen to Rosalie as she was so much smaller.
"I was really really nervous during the birth but when they were born they showed them too which was amazing.
"After they sewed me up they took to me to NICU to see them which was lovely.
"They were just beautiful, especially Rosalie she was so small her nappy came up to her armpits.
Noah remained in the hospital for three weeks and three days while Rosalie stayed in both St Michaels hospital Bristol and Royal United Hospital, Bath for 95 days until she was well enough to go home for the first time.
Loving mum Rebecca documents their progress at home on her Instgram @roberts.supertwins
Rebecca said: "It was amazing to finally have them all home.
"It was hard work going between hospitals to see them for a while but when they finally home was fantastic.
"It was everything we wished for it was a relied.
"It is hard work having twins but now having the family is together is amazing
"Our lives started then after so much worry and we feel like the luckiest parents ever."