Still waiting

So, we tested early and had a negative test. We decided to just wait it out and see what happens. Today oz day 29 of my cycle, my usual start day is 28-30 so we will see what happens. If I haven't started tomorrow we are going to evaluate our next move...do we test at home thursday morning knowing that it should be pretty accurate by then, or do we go for a blood test for an absolute definitive? We will know by tomorrow night what to do and by thursday should know for sure whether we are going to be in a 9 month wait or another 2ww...