Getting bfn

I’m 10dpo and af should start on may 2 and usually I start 2 to 3 days before af is due took a test and came back as a bfn I’m going to wait and see if af comes if not I’m testing again when I first got pregnant I kept taking test but it would say no so I had to do a blood test to confirm it and when I got pregnant with my son I took pregnancy test and it said yes so idk if I should have a blood test done or just wait I’m hoping for a bff