It is indeed possible to still be pregnant with one baby after losing twins. This phenomenon is known as a vanishing twin syndrome, where one fetus stops developing and eventually gets absorbed by the mother's body while the other continues to grow normally. In some cases, the remaining baby may compensate for the loss of its sibling by growing at a faster rate, resulting in a larger belly size. However, it is crucial to consult your healthcare provider for proper monitoring and guidance throughout your pregnancy journey. They will be able to provide you with personalized care and address any concerns you may have regarding this unique situation.