Understanding Placental Bleeding in Early Pregnancy: A 10-Week Checkup

Question
I am 31 yrs old and 10w2d pregnant with my 6th child.  I have had 5 previous NON COMPLICATED births.  Today, after a routine sono, the Dr was going over the results with me and, in passing, mentions that "everything's great" and in the same breath says there was a small "pocket" or "bleed" (can't remember now) to the right of the placenta.  I was floored and asked her what it meant...would it fix itself, etc.  She mentions to me NOT to worry about it at all...it is completely normal.  NORMAL?  I don't think so.  I'd like to think that after 5 kids I have read and seen everything possible.  This is news to me.  I am having absolutely NO bleeding or cramping whatsoever.  This pregnancy is rather easy as all of mine have been!  Please elaborate for me.  She did NOT mention placenta abruptio, just that sometimes when the placenta gets implanted into the wall, some doesn't. Your baby had very good heart tones so I'm not worried, you shouldn't be.  And then she was gone.  Rushed me off with a visit in 6 wks for the more-detailed sono done at 16 wks.  
I am not the kind of patient to call for everything, nor have I had the need to, but she has gotten me very upset with the news.  Should I be?  Or, is she right in saying not to worry?

Thank you in advance,
Sandy

Answer
Don't be upset. It is normal, during the formation of the placenta (between 10 weeks and 14 weeks gestation) to have a slight bleed into the folds of the placenta while it is implanting into the uterus. This is called a "subchorionic bleed" and will not cause any harm to the baby or to you. It usually dissipates on its own within a few weeks. It is similar to when you lay shelving paper down on your shelves and sometimes get a fold in the paper. It is harmless. The repeat sonogram is merely to see how the bleed is resolving. Don't worry. This is very, very common.