Could I be pregnant or not a chance?

I was supposed to get my period June 29. Never came. Im never ever late. Took a couple pregnancy tests. Came back positive and some came back negative. I had a blood test done and they told me I was not. I still havent gotten my period but have had spotting for 2 days. Nothing that i need to wear a liner or anything for. Only there when i wipe and its brown in color. Do i wait and retest or take the word of the blood test that im not. I feel like i am but im not sure.