I have my tubes tied by I kept getting nausea I haven't had my period and im having lower abdomen pain I have taken pregnancy test they was neg what is?

See your doc. I would recommend and ultrasound of the pelvis and possibly abdomen. Maybe some blood tests also. If the pain becomes severe or gets worse, go to the er as it could be appendicitis.
Depends. How long ago was surgery? Have you been back to see your doctor. The cause could be adhesions from the tubal procedure .