What Does Negative Pregnancy Result With Nausea And Sore Nipples Suggest?

I have a question about pregnatcy i been having almost all the signs the nausated in the mornings, my nipples are sore, lower back hurts, i have to pee alot, when i look at food it looks not good but all i been hungry for is vegatbles and fruit, then just recently i been hungry more than usal, looking at soda makes me not want any just tea and water, i did have heart burn for alittle bit. I have also threw up once i just ate and i had to get some food at the store so i went over to the meat and looked at it and i almost threw up right there lucky i made it to the restroom. But i need some advise if i am i have taken several pregnantcy test and they have said negative.