Ok so my period is supposed to start on the 14th but for the past 2 maybe 3 days I’ve been cramping pretty bad and having pretty bad back pain. No tender breasts but nausea here and there and Crazy mood swings. I took a pregnancy test last night and it was negative should I take another one if I miss my period?

Ps. My periods aren’t regular and I’ve never missed a period before. I normally cramp 1-2 days before my period not a week before!

Pss. I recently started taking prenatal vitamins to help my chances