5days late should i take a test

So 1day after af was supposed to be due i took a test and got bfn. 3 days late tested again bfn. I’m now 5 days late but scared to test. I’ve read that you can get a bfp later due to lower levels of hgc in my system. I’m thinking i should wait until I’m 8 days late and then test again. Any thoughts? Oh also, my period is regular right on time every month my whole life. 26 day cycle