I may be pregnant

i don't feel good at all this week. i've had the allergy cold and supposabley it made me have loss of appetite and feel like throwing up to every meal or thing i eat.. My period ended on tuesday but i had dark spotting after which it was weird.. Right now i feel like im cramping and nauseous. 😕im stil a but sick like Runny nose and a musucyyy throat. Do you think im pregnant ? or it's the Allergy flu ? .. i havent took a pregnancy test because i got my period and i heard that if you miss a period then ur pregnant