2weeks late

Hey ladies Af was post to show on 8-18 but was a no show and I'm still getting Bfn 😩but I go to my OB tomorrow do yall think they will check my Hcg though my blood ? And will it show up in my blood if I'm pregnant 🤰 or do y'all think I should purchase a first response today and test again? I haven't tested with a FR in a couple of days