Possible irregular gestional sac

So today I am 4 weeks 6 days. I went to the er for cramping at 12dpo my hcg was 47 14dpo hcg was 123 today at 18dpo I am at 848. They did an ultrasound could not find anything wrong with my ovaries or anything and radiologist said there is a small slightly irregular cystic region that could possibly be baby. No definitive visible gestation sac. If this is the sac can it correct it shape to go on and have a healthy baby?