How to tell difference between early pregnancy signs and being due AF?

I might sound stupid but how do you tell the difference? I have PCOS and my periods are irregular and sometimes very light or heavy. 2 week ago i was spotting for 8days with brown/light blood. I went to doctors & she said I was having an extremely light period. I had sex a few times while spotting. For the past few days I have been having stomach cramps. From yesterday my boobs are feeling sore & my nipples are very sensitive also my vagina especially my clit (sorry for tmi) is sensitive too. Does it sound like I am about to have a regular period? I know that a sensitive clit isn't really a sign of early pregnancy but i am sure everything else is.