I guess (to me) it depends on how/where you are going to cut and your INTENT.

If your intent is to do permanent damage or to possibly kill yourself (or even put yourself in a position where it could kill yourself) - then I think you are obligated to call a crisis center.

If you are just doing some minor self harm (IE glorified scratches - which is what I typically do) - then I do not see a need to call a crisis center (but talking to a therapist would be my recommendation).

Best wishes to you.