Period after delivery.. Question..

So I had my son on Dec. 5th 2013.. I bled for 2 weeks.. Well Feb. I had a period for about a week.. I haven't had a period since then I did however LIGHTLY bleed for 2 weeks it started sept. 17th but it was like a baby pink color and it kinda looked like I was "spoting" I took a test and I see a line but everyone tells me I'm seeing stuff. What could this be.. I have irregular periods to begin with but I never go this long without one.