I've been in pain does this mean I'm pregnant?

Ive been so hungry lately and having bad backaches and glow said i was supposed to have my periods 3 days ago but it never came. Also my breasts have been aching and i only weigh 109 and ate 5 tacos and the next day 3 tacos and yesterday two fried fish and yet after reading so much i be hungry all over again as if i never ate. Am i by any chance pregnant?