Is it possible to be pregnant after getting a BFN?

It's about 3 weeks ago I had what I thought would be my IB I took two test 2 weeks after and came back both negative, I've been having all early pregnancy symptoms but idk it it's still possible to be pregnant or not. Since I think being 3/4 weeks pregnant it would show up on the test but came back negative.. Please comment if you had something similar if I were to be pregnant I would be a month now, but got two BFN thank y'all in advance. :)