I just talked to a dr (not mine, but from my clinic and he was very very nice) who was able to answer some questions for me :) He said that abnormally shaped yolk sacs are not uncommon and not a reason for concern unless there are signs that baby is struggling. (not growing right, low heartbeat...) I also mentioned that one babies gestational sac was smaller than they'd like to see at this stage but that they didn't seem concerned and he said thats fairly normal too. He said that he looked and he sees no reason for concern, just a few things to check on in a few weeks. He said, since babies are still growing normal, appear normal and have good strong heartbeats he's totally fine with it. So YAY! He made me feel much better!!