Yeah your a bout right. I was drinking 3 or 4 beers that actually was kinda a sign of my pregnancy, because I got sick. For a whole week after I drank I felt sick to my stomach and I took a urine pregnancy test and it read positive.( just to let you know I wasn't sick from drinking beer itself but I was sick because of the fact I was pregnant and drinking a harmful substance to the fetus)
Having a beer has nothing to do with the pregnancy test. It is the hcg levels in your blood stream. These are hormones.