if i am spotting brown discharge does this mean i am pregnant

Ok so i been off depo for about 9 months now, my periods for the last two months have been normal they both started on the 17th . Well this month it started on the 17th and my first day i was heavy and the other days i am spotting red and brown. I am cramping in the lower abdomen, i have back pains every now and then , and i get head achs. Lately i would have just ate and like a hour later i would feel like i been starving for days. My last two pregnancy i didn't have any symptoms that i know of. So my question is does it sound like i am pregnant and if so when should i take a test if i am done spotting.