What Causes Dizziness, Headache And Delayed Period While HPT Is Negative?

I had my tubes cut about 9 years ago and for over a month I have been dizzy headaches stomach pain weight gain fatigue back pain emotional moody food craving I had a normal period the first of January and one not normal the middle of January and did not have one so far this month I was supposed to on February 1 I took s over the counter pregnancy test today and it was negative