Should I go for a blood test?

Bianca
Been TTC for 4 months, was on depo for 3 yrs but been off it for about a yr and a half, was then on the pill. My cycles were regular 28 days, last month was 30 days, now it's been 33 days since my last cycle, took two pregnancy tests, both neg. Should I see if I can do a blood test at the Dr's or wait longer to test?