My breast are tender, big appetite, lower abdomen pain and side pain, and weird movement round my navel. itook a pregnancy test it said negative.?

Certainly: While those symptoms can occur in early pregnancy they can be associated with a lot of other conditions. I would recommend a doctor's visit.

Miss period?: If you had sex since your last period and missed your period by 4-5 days do a home pregnancy test. Alternatively you may get a blood test for HCG level. From your description you need additional history, physical examination and may be some tests. It would be prudent to see your doctor. For nutrition: http://www.choosemyplate.gov/.