Oooh sorry I didn't see this thread before. I've had similar things in the past...it's important to note from a completely non-metaphysical viewpoint that crows are very intelligent and curious creatures, and very attached to their own territory, so it could be they have "moved in" and are sussing out whether you are a threat, possible source of food, whatever. For example, we had some who would watch for when the dog food went out but the dog went in and then hop down and have a feed

The other thing is that the symbology of crows (and ravens, because they could actually be ravens) is that they tend to be viewed as messengers from spirit, and not necessarily "bad omens". They also govern things like exploring the hidden realms, shapeshifting (in a shamanic sense), and altered consciousness. It's up to you to explore intuitively whether you feel the universe is urging you to "pay attention" to something at this time (information coming) or whether it's just a natural occurence.