So, I just had my second OB appt with this pregnancy and my first ultrasound to check placement of the fetus, heartbeat, etc. The baby he could see in there looked normal, growing at the appropriate rate and with a strong heartbeat, but there was also something else taking up almost half of my uterus. The doctor said this is a vanishing twin, basically a twin conception but one baby didn't make it. He's going to check me again in 4 wks to make sure it's absorbing back into my body as it should. He seemed pretty clear that this shouldn't put the other baby at risk for any problems and these types of pregnancies typically continue on as a normal single pregnancy. Has anyone else had this happen before? Did you go on to have a healthy pregnancy/baby after the fact?