Avoid any blue dye tests. Notoriously bad and most people end up confused or having to retest. First response is honestly the best I have found and read reviews about. Also, I suggest waiting until at least 10dpo if not 12dpo to reduce costs as can get pretty expensive.
I have also bought test strips from eBay which are vey economical and I go nuts testing with these since they are maybe 50 cents each