Late period

Kala • 19 || shy, bi, and ready to cry. || I read tarot cards and collect crystals 🌿
How likely is it that a pregnancy test would come out negative five days before a missed period even if I was pregnant. I was feeling pretty sick and dizzy and short of breath and moody so I went ahead and took one and for a big fat negative but my period is late (only by a day) but I'm getting really anxious about it.