Your body kicks into a miscarriage because chromosomes don't go together obgyn explained when dna doesn't fit right together that is what happens.
This happend to my sister in law . She found she was pregnant with triplets at first appt and then when she went back there was only two and an empty sac . They explained to her that she had lost it and that her body would absorb the rest.then when they measured the other to sacs , only the one baby had grew and the doctor told her the same this was gonna happen to baby 2 that happen to 3 . Now she's 18 weeks with just one healthy baby . It was very sad , but we are happy that one baby made it and is doing great . I'm sorry this happend to you , but god is in your corner an you have one healthy baby .
Apparently it is not common but not rare at the same time. They say because were able to have early scans we detext these things, by 12 weeks ill only have the one baby and sack so would never of known.
Have to be positive, yes twins would of been wonderful but one healthy baby is good enough for me xx
Sorry that happend to you but things happen for a reason. God knows his plans for you and maybe it wasn't your time for twins. But I'm happy to hear how positive you are taking the situation.