I've missed my period and am having pelvic pain on the left side mainly and my back hurts and I've had nausea all day what is it? Pregnancy test are -

See a doctor. It might be too early for otc pregnancy tests to be accurate. I would see a doctor for further testing.
Depends. Go to ob-gyn.......You should repeat preganancy test.....If it is definately negative many reasons including ovarian cyst, etc.