Miscarried one of my twins

I have never gone through a miscarriage before. I was working so hard at my job at the time of the miscarriage that i didnt know it had happened or that i was pregnant. I was 10 weeks when i found out one night in the er that i had twins but lost one 3 weeks before. The doc said that there was no heart movement and it seems as if it never formed a heart in the first place. Im 16 weeks now and still wondering why this had happened. Why did my baby grow for 7 weeks if there was no heart? I havent seen a real obgyn yet im waiting for my insurance to go through so i have only talked to emergency room doctors. During the ultrasound i can see two sacs and in one is a baby and in the other looks like a seed. People tell me its wrong to grieve something that never had a heart but that seems too hateful it still was my baby at one point and it grew inside me. Just feeling depressed and dont know what to do...im very tired but cant sleep and my back is killing me plus heartburn. Still prego but grieving for my loss