An extremely rare phenomenon caused a mother to fall pregnant again, having already conceived a baby boy. The “twins,” who were conceived three weeks apart, caused a stir among doctors before their birth via Caesarean section in September 2020. “I didn’t even know it was possible to conceive again while pregnant,” Rebecca Roberts, 39, told the Daily Mail. Shocked to learn she was expecting twins, Rebecca, from Wiltshire in England, was told that a rare event known as superfetation had allowed her to conceive a second baby while already being pregnant. However, Rebecca’s early pregnancy scans had not picked up on the second fetus. It was only in her 12-week scan that Rebecca found out she was expecting twins. The mom of three, who runs a children’s clothing company, and her 43-year-old partner, Rhys Weaver, were advised that a fertility drug Rebecca was taking may have prompted the release of an …