Does Ahimsa effect your Karma?
Yes, surely. Ahimsa (non-violence) is a quality of good people. It will add to the good karmas if violence is avoided where it can be avoided. Lord Krishna said in Gita:
BG 16.1-3: Fearlessness; purification of one's existence; cultivation of spiritual knowledge; charity; self-control; performance of sacrifice; study of the Vedas; austerity; simplicity; nonviolence; truthfulness; freedom from anger; renunciation; tranquility; aversion to faultfinding; compassion for all living entities; freedom from covetousness; gentleness; modesty; steady determination; vigor; forgiveness; fortitude; cleanliness; and freedom from envy and from the passion for honor — these transcendental qualities, O son of Bharata (Arjuna), belong to godly men endowed with divine nature.
BG 16.4: Pride, arrogance, conceit, anger, harshness and ignorance — these qualities belong to those of demoniac nature, O son of Pṛithā (Arjuna).