Feeling annoyed and anxious!

I have never missed my period by more than one day and even that has only happened maybe 3 times, and this is going on day two. I am having light cramps and an ache in my public bone area...also bloated. I had a neg test at 13dpo and the day my af was due but that day was not fmu. I don't want to test because I feel like it would have been positive both those times if I was pregnant. I'm getting very anxious because this has never happened to me! Does anyone have advice?