am i pregnant ?

hi im 31 years old i not sure if im pregnant i took urine test thats came negative a couple took are from dollar store 1 i took today was a u check from the dollar store and on august the 8 took a clear blue test digtial came negative on 10th took another clear blue negative still havent got my period my period doesnt come regular so not sure but in july period was july 8 and last period was August 5 to august 11 was i even ovualting? back to this part ok had sex august 14 start spotting august 19 a bit pink more red light with a bit brown 1 time i wipe was a chuck of red blood but just one time not even sure if i was ovulating still no period and its september 14 today again period is not regular been a mont so should i rely on the negative tests?