opinions?! I am a mental wreck this week!

I am trying not to get my hopes up but feeling like this could be it!  Period is three days late and is normally on time like clockwork, I had a weird pain in abdomen for about 12 hours unlike any menstrual cramps I've ever had  at 12 DPO. The last three days I have been So unbelievably nauseous and dizzy, and have a dull pain in my lower back. Three negative tests so far... should I wait another week? I am so anxious, I can't concentrate on anything else!