I had one this pregnancy. They found it at 6 weeks and it was gone by my next ultrasound. I never had any bleeding but they told me if I did that it wouldn't be a bad thing necessarily. (They did tell me to still go ahead and call if I did have bleeding.) Mine was reabsorbed by my body and we would have never known I had it if not for that ultrasound. So it may just be nothing and resolve itself, or it may bleed out a little.
Me (29) DH (30)
#1-Olivia Caetlyn-9-28-09-9-28-09, 23+2 wks, emergency classic c-section, class I HELLP, IUGR
#2- Lucas Oliver (rainbow baby)- April 2011, 36+2 wks, HELLP and pre-e free! (lovenox and LDA pregnancy)
#3-Matthew, late October 2012...mostly normal, 37 wks, (lovenox and LDA again)
My blog: http://www.butterflies-and-rainbows.blogspot.com/