I want to test !!

I normally have a 28 day cycle but last cycle was 31 days I believe due to stress. I'm on cycle day 29 and made it a point not to stress this month but I dknt know if I should wait until cd31. I think I SHOULD but don't know if I can lol esp with a test sitting in my room ! What do u think ? Should I wait to avoid a false bfn? The test I have is a clear blue early detection test