5 days late, not sure if I'm ready to test yet

Ma
Hi there ladies! I am 5 days late and have been thinking about buying a test but I have zero symptoms, and I'm thinking that the delay  just due to stress and not pregnancy. I don't want to buy a test just yet incase it is just me over stressed and delaying my cycle. 
Do you think I should buy one? Or wait a bit longer before jumping to test?