why do AF and BFP symptoms have to be so alike 😩

Ba
So frustrating that these symptoms are so alike X usually 2 weeks prior to AF my boobs hurt like hell and the week before my CM dries up and I get PMT ... AF is due in 4 days and my boobs still arnt hurting , just my right a slightly sore, my belly is rediculously bloated, my CM is creamy , I've a cold sore, been having migraines and lower abdo pinching and thigh pain!!!!! Some mixed symptoms : wonder if AF will show her ugly face or if we will get our BFP