What Causes Light Periods, Lower Abdominal Cramps And Breast Tenderness?

Hi I started my period april first which was right on time but it was very funny right off the bat. I had bad cramps and it felt more dominant on the left side. I ended up almost fainting and went to the doctor where they said that your hormones are off during this time and that could have affected my blood pressure and mad me feel that way. my bleeding that day and the next was extremely light like it was the end of my period. Then all bleeding stopped for about 3 days then i noticed a small amount of brownish spotting that lasted half a day and went away. Ive also been experiancing mild cramping in my lower abdomen some breat tenderness and I am exhausted have had mild headaches off and on along with nausea. I took two home pregnancy tests and both were negative but i am just not sure.