or your body will just reabsord it
I had this happen to me in one of my pregnancies, I started bleeding, thought I was having a miscarriage, wrnt to have an ultrasound and it showed 2 sacks, one was viable and one was mishapen and on the way out, so I was infact having an early miscarriage, but only one, the other stayed out and I now have a healthy 3yr old, your body has produced two eggs, both have been fertialised and only one has continued to develop as it should by the sounds of it, going by what happened to me, hopefully it will pass with no trouble