It's true, crows are negatively viewed as harbingers of misfortune in Western society largely due to Judeo-Christian influence. This has much to do also with the way we see death.
In the Celtic pantheon, the Morrighan is the goddess of war, death, and prophecy; but also of fertility and healing. Her 'familiars' (for lack of a better term) are crows, ravens, and wolves. Many Dualist Western minds find it difficult to reconcile the goddess of death and war also specializing in healing and fertility; but this is a reflection of the beautiful balance that is life here in this realm. Morrighan is not to be feared, nor is death, nor are crows. It is a part of reality that our ancestors dealt with FAR better than we do, as a rule, in Western society.
Generally the Morrighan - or her crows - brings a message of needed ruthlessness. What I mean is this: crows clear the ground; they are carrion birds. They feast on dead flesh; thus clearing the ground for new life to spring up. When Crow comes to you on a consistent basis, one thought you might explore is the need to clear some ground in your life; are there things hindering you in your life path that you should get rid of? They need to go; it's dead flesh, don't let it rot on the ground.
The Morrighan as a healer is far different from our traditional ideas of healing deities: she is not a nurse, or a gentle sort of physician - she's a surgeon. If she sees something needs to be cut off, she will do it. It will at times hurt like F*** when the Morrighan heals; but it's always necessary and usually an emergency. Crows and ravens are her agents.