Help!!

I started my period on April 4th and it ended on the 6th. Today is April 17th and I am now having some mild cramping and I'm bleeding again. Not a bunch of blood and it's brown. It surely can't be another period coming on. Before my period I was convinced I was pregnant. Sore breasts, bloating, weird cravings but all BFN on home tests. I even went to planned parenthood and they tested me, BFN too. Then all of a sudden my period started. Now it seems like I am starting again. Which I don't understand? Anyone else have this issue? Can someone shed some light on my situation?