Should I retest?

I started bleeding Wednesday but I wasn’t supposed to start my period until today. The bleeding was very light, all I used was a panty liner. The blood was bright when I wiped. The bleeding stopped yesterday. My periods are usually very heavy, and at least last 5 days. I took a test Thursday BFN and a test Friday BFN. Today my lower back and butt are so sore. Should a take another test? I’m just scared to see another negative