Am I Still Pregnant With Negative Pregnancy Report While Suffering From Headaches, Dizziness And Delayed Period?

My period was 5 days late which is very usual for me because I have very heavy and regular period almost to the exact minute and hour.. The day that my period was supposed to come I could hardly get out of bed because I felt as if I would throw up and very dizzy.. When I got what I thought was my period, it was pinkish brownish but most of the time brown or almost black looking.. It was very very light and had little cramps which also very strange for me because I normally have horrible cramps as well.. Ever since I missed my period the following week I have had headaches, get dizzy a lot, feel as if I'm going to throw up, back hurts in the lower area, I have some cramps in my lower stomach, in my panty line area, my boobs have grown a little and are very tender all the time, I am always sleepy, and I have to pee what seems like all the time.. I have taken 3 tests at home and 1 at my health department all by unrination and all came back negative. Could I still be pregnant.?