am i pregnant but 5 pregnancy test have came out negative ?

[Chels]

I am 17 and i did have my period 2 weeks ago but it lasted 1 1/2 days and it was very very light and a light pink i am bloating and my stomach is harder than usual and i am urinating more than anything and i am having mild cramps a couple times a day and feeling sick in the mornings and sometimes after i eat which is alot and sometimes my lower back hurts but all the pregancy tests comes out negative what is wrong i know i need to go to a gyno