I need a little advice!!!

I had a miscarriage in May. Once I stop bleeding I started back. I had a period after that. Now it is August and my period is late two days. My last AF was July 13-17. And my AF was supposed come August 6. I have had sex since then. I told a test 3 days ago and it was a BFN and I took a test today it was a BFN. So I look at the up the weeks and it said 3weeks and 4 days since my last period. I am getting sad because I know I am but the test are reading BFN😔. My questions are is it to early to read and should I wait longer to see if my AF don't show.

Please help me

Sorry for no pictures of the test I was sad throw them away