6 days Late and 20DPO

Hello Ladies. I hope someone can give me a little piece of mind.

I am normally on a 28 day cycle and maybe 1-2 days early or late. This month however, I am 5 days late and 16DPO. I am on day 34 if my cycle. I hate waiting on AF, but Idk what to do. I took a HPT yesterday and it was BFN but still no AF. I have some symptoms (irritable, light cramps, nausea, back pains and fatigue). I have not been stressed and nothing has changed diet or exercise wise but something it definitely different. Should I wait until 7 days late to take a HPT or should I make an appointment to take a blood test??