I haven't had my period in two months and took a test and I'm not pregnant. Im not sure what's going on!

There are a few things that can cause your periods to stop. Too much or too little weight, hormonal imbalance, stress, certain disorders (I went a year without a period after being on and off for three months at a time the year before and found out I had Polycystic ovary syndrome)
I would recommend going to your doctor.