fibroids hiding baby?

Babebaby

My LMP is January 18 and i have fibroids that are a good size...

I had an ultrasound last week and the u/s showed something in the sac but we couldnt see the heartbeat so the tech felt it was too early and i asked that i come back this week. The ultrasound was both vaginal and abdominal.Today when i returned we could see now a large sac but no baby (abdominal, we didnt try vaginally). The doctor says its possible that it could be hidden behind the fibroids. Has anyone ever exp or heard of someone exp this?