Help me please .

Okay I recieved my period 8/27/15 it lasted for 12 days started off as very light pink went to brown to red to dark red to bright red to brown to pink . then after the 12 days I started spotting pink after like sex, and after I urinate and what not. I had bad cramping during my period . not extremely bad but mostly in my lower back I didn't receive a period since June 17th.period is normally 4 days. Should I be worried or should I take a pregnancy test ? But when I had my period I didn't need to wear a tampon maybe just alittle pad . and keep going . now I'm not sure how to track my ovulation or anything cuz my period lasted so long. Please help thanks