5-6DPO

so i tested on september 5th and got a positive LH surge, except i tested again 5 hours later and the surge had ended, but i thought normally the surge lasts at least 12 hours? so i’m thinking i caught the very end of it, i had EWCM two days before (but at like 2am) so im thinking i’m 5-6 dpo. the past few days i’ve been literally SO nauseous, and having insane food aversions. is it possible to even be having symptoms this earliy?