I’ve looked up Vanishing Twin Syndrome, and almost every article I have seen said that VTS typically only happens during the first trimester of the pregnancy.
But here’s the catch: My mom didn’t realize or know she was pregnant with me until 7 months into the pregnancy. And when she found out, the ultrasounds did show two babies. Me and my twin.
If Vanishing Twin Syndrome usually only occurs during the 1st trimester, is there a reason why it can happen so late during the pregnancy, as in the case with my mom and my twin? Or is there technically another name for this specific situation?


This whole thing is in violation of Rule 3.
But if you really want the speculation of an unqualified guy on the Internet. Here be pain. You have been warned.
Depending on the country, the era, the hospital and the prevailing mentality and procedures followed by the medical staff there, it is a possibility your twin was not viable ex utero. The doctors might have hidden it away and then spun the tale that the twin had been absorbed to save your family the anguish and pain.
Why not let a newly-blessed family go home with their one happy, healthy child and none of the pain?
The alternative is that your twin is was viable but was stolen away to be raised by someone else. But that sort of thing usually only happens in TV melodramas.
Don’t know if this would help, but this happened in the US in 2003-2004. (My mom found out she was pregnant with me and my mystery twin December of 2003 and two months later in February of 2004, I was born)