Could i possibly still be pregnant?

my period is now a week late, ive had bloating, and through out this whole week ive had the cramps that i get while i am on my period. but no blood has come out. my are sore. my have kind of changed in color and the aerola has gotten just a bit bigger. they are also very sore. i have been feeling quite nauseous every once in a while and the smell of chocolate, takis, and any sort of junk food makes me want to throw up. my nose seems to be getting more and more sensitive. i have also have had this faint headache that goes and comes back. all signs point to pregnancy right!? welll i took a home pregnancy test this morning and it came out negative.. my question is, is it possible for me to still be pregnant? should i wait a few more weeks and retest if no period? or should i go to the doctor for blood work? thanks for the help (: lots of points to the best answer(: