Extremely Light Period and Negative Pregnancy Test

I was supposed to start last Wednesday and I have had some very light spotting only on the TP when I use the restroom since. I took a pregnancy test when Glow said I should and it was negative. Normally my period is on time and medium flow with cramps...I haven't had to use a tampon or anything really. Don't want to get my hopes up that I had a false negative...could it be possible??? No other signs.