I’m 6 days missed and 19 dpo, confused.

So i am 6 days missed period, and 19 dpo i tested the first day of my missed period that was monday it was negative. and i still haven’t received my period. i have cramps, discharge and nausea. I am not stressed but keep gettting negative tests. but i tested at night 3 times Should i be concerned? I have been cramping since the first day of my missed period. Should i take a blood test. I’m never this late before ever 7 days is the longest i have gone. my cycle is 7 days or sometimes 5 i never even missed 5 days or 4 before the most was 1 so Yes today i am 7 days late with cramps since monday with no period.