What I found online: mosts cysts go away, are really common, and aren't a problem, however, they might need to be monitored if you experience heavy bleeding. (And this might be more to keep you comfortable than anything serious)
There is a tiny tiny chance that it could be ovarian cancer, but that;s really unlikely. And as long as it's not, chances are, your fertility it perfectly fine.
I don't think you're at risk to get more, or that it's something to worry about. But do tell your doc about the bleeding.