I Got a Question Ladies

Wats good? Ok im 32 weeks preg. I call 32 wks (8 mts). Wolud you? See I think doctors count by every 4 wks right? Because up until I was 28 wks preg. I was going in for my" monthly visit " every four wks. The reason I asked is because my due date is on oct. 27th and someone was like " well how could u be 8 mts pregnant if your not due for like almost 2 mts? Plus, soo many people say that were actually preg for more than 9 mts cuz we are preg for 40 wks....And 40 wks is almost 10 mts. So does anyone know what im talkin bout?