Is this mold on my room's ceiling? Is it dangerous?
They definitely look like water spots or leaks. You stated you've been in the attic and saw no sigh of leaks... have you been up there lately and actually looked at the drywall where the spots are? If no signs of any leaks, blotch some bleach over the spot. If it's an old water stain that might remove it. If you do paint, get a stain blocker and apply it per instructions before painting.  It really does not look like mold. have you ever had any rodents up in the attic??