Could I be pregnant or is it just my cycle?

Ok for the past 2-2 1/2 weeks now my breaast have been sore but not to where i couldnt touch them and ive been having a chalky white discharge no odor to it. I thought maybe its my cycle coming but my breast never hurt and ive never discharged like that a whole 2 weeks in a row. i had my cycle for last month i knew it was almost time for it 2 come again which yesterday evening when i got home, use the toilet, i saw very little light pink spot. this morning when i got up use the toilet i saw a little more than yesterday and jus a tad bit darker. and now im having light cramps and it feels like somethings pushing down on my lower back and pelvic bone and feels like needles sticking me. Idk if this is my actual period or is this early signs of pregnancy. I took 2 pregnancy test both neg. Cant afford a blood test right now. Can sumbody please help...The only reason y i need 2 no now is because i was suppose 2 b getting diet pills and the dr. wont prescribe them 2 me bcause we r both unsure and i cant wait another month 2 c if i miss a period. i need them now.