Blood covering malformation on MRI/MRA

My fiancé had a MRA on Monday as a follow up to a MRI he had a few weeks ago that showed possible vascular malformation. The doctor said the MRA didn’t show anything because whatever is happening in his brain is currently being covered by blood…so clearly that means that his brain has already bled. The doctor suggested we come back in 6 to 8 weeks for new MRI/MRAs. I guess I’m just confused about the whole thing. My main two questions are:

  1. How can he have blood just hanging out in his brain causing no problems at all?
  2. Where is it going to go?
  3. Is he going to have a stoke or something in the meantime?

The doctor suspects a cavernous malformation because he said if my fiancé had an AVM the bleed would have been much more severe. Has anyone ever been in this type of situation?