How many dpo??

Stephanie
I am 17 dpo today and suppose to have my period. Just took a pregnancy test and it was a bfn. Should I just wait until my 'period' time is completely over to do another test . I feel like I shouldn't even try again . I keep getting disappointed. Or maybe I'm one of those people who can't get a positive till after 2 weeks after their expected period . Gosh darn