Spotting?

Savanna • Hi💗 Just a girl with a lot of questions✌🏼️
My period is suppose to start in 4 days and I'm getting a lot of brown discharge for the past three days, well not a lot but enough. I switched pills this month (starting taking them immediately after my last placebo like the directions said and never missed a pill) and me and my boyfriend don't use condoms. Could I be pregnant? I took a test this morning and it was negative, what is this?