Please tell me what's going on!

So I'm 8 days late with my period, I'm nauseous, my bbs are soo sore (never this bad), had some brown bleeding last "period" and craving so much, etc. I took 3 cheap tests and 1 more expensive one. And they are negative. Is it possible that the tests can't read the hormone yet at 8 days late for period? If any one had anything similar please let me know! Thanks!