period and formula feeding... help!

Ok tmi I know but I bled for about three weeks pp, then it stopped and came back about two weeks later, so I thought it was maybe my period. That lasted for about four days then two weeks after that I started bleeding again and it's lasted for over a week! Is this my period? Why is it lasting so long and why am I bleeding again after just bled two weeks ago? Anyone else who is not breast feeding have similar problems? (I say that bc I know breast feeding does wacky things to your perios)