Sex protection unu


so, my period is now late for 20 days and since 3 days of the missed i took 4 pregnancy test per week till now and ALL WERE NEGATIVE. Also we USED CONDOM THE LAST TIME WE HAD SEX and we always check the condoms and they weren’t broke or something and he didn’t came inside me so... WHY IS MY PERIOD EXTREMELY LATE? Should i take a blood test? O what? Im so scared but i dis everything the right way 😭 why is still late my period?