Hello, Im bleeding and not on my period. Im sexually active. I don't know what's going on. My last period was on Sept. 5 and I started bleeding today(Sept. 16). Can someone help me?

It may be implantation bleeding due to pregnancy.

Do you have irregular periods? I have been known to go a month or 2 without one, then have one, and then have another 2 weeks later.

I would say its time to see your doctor hon. We can only help so much without seeing you in person.

I don't usually have irregular periods.. my periods usually come every 21 days. Can implantation be a little more than spotting? This bleeding is lighter than my normal period but it isn't spotting. I have a period every month but this month I had two.

If you are on birth control pills, or other hormonal forms of birth control, they can sometimes cause bleeding or spotting between periods as well. If you had recent sex, it could be from that. Might be from a cyst, could just be an off cycle... there are a number of possible reasons. Often times it happens and is gone and no reason is evident.
See how it goes... if it continues, causes you pain, or just causes you concern, ask your doctor about it as jenniepepsi suggested.