Am I pregnant? Should I do blood test?

I am a week past my normal period start date. I have taken 3 pregnancy tests and all have come back negative. I have had a few possible pregnancy symptoms but most of them can easily also mean I'm about to start my period. Should I just wait longer and see if my period comes or what? Should I go to the doctors and do a blood test to get an obvious result or is it too soon? Thank you!