I had a tubal ligation about 12 years ago and I'm feeling a little weird. Had a very light period on about the 20th June about 3 days and was feeling dizzy light headed and vomiting, pain on my side. I took a pregnancy test and the result was negative but was not sure because the test result was very light. My question is could the test result be wrong?

It's possible. BUT it could be something else as well. How old are you?

Unlikely but always possible. It could even be a cyst on an ovary, or, if it's on your right side, an appendicitis.

Why not make an appointment with your Gynecologist to find out for sure.