Movement In Stomach, Constipated, Thirsty, Hungry, Mood Swings, Blurry Vision. Am I Pregnant?

Hi, i am having movement in my stomach, like baby kicks, I have a 4 year old son, I can tell what this feels like. I was constipated for along time there for awhile but now I am feeling normal in that dept. I am excessive thirsty and seem more hungry lately. I am having mood swings like crazy. My vision has been blurry and eyes been dry. I am tired all the time. I feel naseaous on occassion and my apetite has increased. I have lost weight but my stomach is becoming more and more pushed out at the lower end. I haven t taken a test in a little more than a month but prior to that I have had all negative tests and I could not be feeling the movement in my stomach unless I was between 5 or 6 months pregnant which puts it about right for conception . Am I pregnant? Is there a medication that blocks the HCG hormone? I need an answer because of the type of medications I am on.