Go see a doctor right away and tell them your problem!!!
I started to bleed around the time I was supposed to get my period and since I have irregular periods I thought this was just one of those times. So I had been bleeding for three weeks at that time and I went to the doctor and he told me that I am pregnant. The bleeding has continued on since then.
Everyone is different though. Have you had sex since your last period? Does the blood look any different sometimes? Is it darker or lighter? Are you passing blood clots?
I really suggest you go see a doctor soon so you can have some tests done. Whether you are pregnant or not you still need to find out what is wrong, it still isn't normal.
I hope everything goes well for you.