Help please

So I took a pregnancy test a week ago, which said positive but my bf's mom wanted to see so I took another one today and it said negative...I'm a little scared and confused. when I took the first one, a lot of other things were blowing up in my face and I was so lost, my friends or myself couldn't stop myself from drinking, when they asked what was wrong I just drank more n faster......do you think I caused the negative one today?