It's been 4 days since I've missed my period. I'm having a little bit of pregnancy symptoms such as slightly sore breasts, darker areola, they appear fuller, and the veins are more viable. A day before I missed my period I had a little brown discharge accompanied by clear watery discharge. That lasted for about three days, then it turned white. I've also have some back pain, and get lower abdominal cramping here and there as well. I'm worried because I took a hpt today and it came out negative. Is there a chance I could still be pregnant?