I'm so sorry..that must be so hard to be worried about this and have to wait to find out more info.
I am certainly not an expert, but there are different types of hemangiomas. My daughters (and most of the people I run into here) have infantile hemangiomas which are not really visible at birth but then shortly after start to grow for about a year. Then they start to go away. But there are other kinds... called RICH and NICH, I believe, which is a Rapidly Involuting Congenital Hemangioma and Non-involuting Congenital Hemangiomas...I don't know that much about them, but I think they are present at birth and I think may be detectable by ultrasound. As far as treatment goes, I think it depends on what type you are dealing with. Could you consult with a Vascular Anomaly Specialist? ...I'm not sure where you live, but there are some suggestions on this site. That might help to put your mind at ease. Then they could monitor it closely for you. I don't think you need to be too worried. Good luck! Maybe someone else will come on here who has had a similar experience. Keep us posted! Hang in there!