should I retest?

Jessa

so I went to the Dr to get blood test done at 12 days late. It came back negative. I am currently 17 days late. No sign of AF. next Wednesday is supposed to be my period for this month. if it doesn't show should I retest or see my Dr? or both? I'm just confused because I never am late with AF. I really thought this was going to be the month. Idk help a girl out.