No period, negative test

I am so confused and not sure what’s going on. My period was suppose to be here this past Friday sometimes it’s a day early or one day after. I’ve been having bad lower back pain for over week now. Eating like crazy. My nipples have lot of bumps on them and they are sore. My period hasn’t started and pregnancy test have been negative. I’m not sure if my period is just gonna be late this month which usually isn’t this late a day early or late is the most or I ovulated late and it’s too early to take a test. Any opinions?