I accidently cut the tip of my finger off while making a birdhouse this afternoon should I see a doctor?

Yes. Assuming it is an avulsion (i.e. No bone involvement, in which case it would be an amputation), this should be seen by a doctor for bleeding control, evaluation for antibiotics, and a tetanus update. If this is an amputation, then a definite yes to see the doctor.
Cut tip of finger. Stop bleeding, tetunus vaccine, may need graft to the tip to close the open wound. See a hand surgeon or a plastic surgeon.