Can a pregnancy test be a false negative ?

My blood test came out negative today but why do I keep getting faint positive lines I don’t get it all the different brands of test I took had faint lines has anybody been in this situation before I’m starting to think it was a false positive more pictures will be in comments

I took a pregnancy test this morning, it was a negative.. so when can I test again before I say i give up.. I'm also 15DPO

So I went to the OB today and they said the test was negative could that be false

6 months and through out the 6 months of taking pregnancy test expect one was positive and the rest were negative. I hoping this time around its going to be positive I dont think I can handle another negative test. 🥺