is it possible that 4 at-home tests are giving me a false negative?

my period is 7 days late today. i haven’t had any signs of my period starting besides some light cramps i had this morning but i still haven’t bled. i’m nauseous and have had an elevated body temp. to explain - my body temperature is normally around 96.8 (yes i know that’s low but it’s always been like that, same for my dad) but the past week its been between 97.8-98.2. and it said online that it could point to pregnancy. i’ve taken 4 tests and they are all negative. is there a chance they are wrong? would a positive result show up by now or am i taking the tests too early?