I've read that women can get pregnant the second time, even when she's already a few weeks pregnant. ok...let me digest that first.
It seems that women have the capability to still ovulate even when she's a few weeks pregnant. So, if a women gets pregnant and is still active sexually, it can likely, though these cases are rare, that she can get pregnant again. Her uterus having a fetus acquires another fetus, resulting to two babies but not twins. Which means, fetuses will age differently and most likely be in different sacs.
Hmmm...so it is fairly possible that a woman, who've had multiple partners can give birth to two different babies with two different fathers. Thank God for DNA testing....sheeesh
This phenomena happens to animals too.
below is an article from the Telegraph, a UK paper.
Mother in double pregnancy gives birth to daughter
By Bruce Johnston in Rome
AN Italian woman who became pregnant with one child and then concieved triplets three months later
given birth to a daughter.
Flavia D'Angelo, 20, whose condition was said to be caused by ovulation continuing after her first conception, is now expected to return to the same private clinic in Rome in March - this time to have another girl and two boys.
Providing that there are no complications, she is expected to become the first woman to be pregnant continuously for 12 months. Specialists say she is a rare case of superfoetation - the presence in the uterus of two foetuses caused by fertilisation at different times.
Flavia's parents, anxious to avoid the media, avoided making any official statement about the birth on Saturday of their granddaughter, Denise.
Instead, they announced the event in Italian tradition by hanging a pink ribbon in the window of their grocery shop in the town of Ascoli Piceno, 20 miles inland from the Adriatic.
"The baby is fine, and so is my daughter," said Giuseppe D'Angelo, Flavia's father, adding: "You can rest assured, soon the others will be coming into the world as well."
His comments came in response to media speculation that Flavia's condition - first announced on Italian state television before millions of viewers nearly six weeks ago - might have been invented.
Her husband, Riccardo Tarquini, said at the weekend: "The baby is bellissima, she weighs 3.4 kilos, but for the moment you will not be able to see her."
He denied reports that there were exclusive pictures of Denise with her still-pregnant mother. "There are no photos. Later on we'll see, but for now we want to be left in peace. It was a natural birth, handled by our trusted doctor, whose name we won't reveal."
Prof Giovanbattista Serra, head of the obstetrics and gynaecology unit at Rome's Cristo Re Hospital, said that while there had been some precedents, Flavia's case was highly unusual, and was due to break records.
"There have been other cases of superfoetation, but usually the time distance between the two fertilisations is one of just a few days," he explained.
"Instead, Flavia's case is the one in which the distance between the two conceptions is the longest ever."
The professor, who was not treating Flavia but who appeared on television with her, confirmed that there had been speculation that she had taken hormones, but said she had denied this. "I think she was telling the truth," he said. "She seems credible."
Speaking about her pregnancy last month, Flavia said she was in awe of her condition, both "overjoyed" and "scared" about the outcome. "I still don't know how the births will work out," she told the popular Domenica In programme.
She and Riccardo, a 25-year-old marketing consultant, met in a centre for the blind in Ascoli Piceno. Training to be a teacher, she was doing volunteer work and he was working as an alternative to military service.
They married, and soon Flavia was pregnant. It was only later during tests that they learnt of her condition.
"My first reaction when we realised what had happened - maybe it was a case of nerves - was to burst out laughing, while she burst into tears, and kept on asking the doctor to take a closer look," Riccardo said.
When the news broke in Italy the couple took a week's holiday to escape reporters.