pregnancy?

over the past week or so I have been eating non-stop and constantly crave food. I am not exaggerating when I say that I have not felt full in over a week. also, my nipples have been tender and I have been having weird mood swings. the other day I started sobbing because I couldn't find anything I wanted to eat, and suddenly began to laugh, and then I just kept switching back and forth. lastly, over the past few months I have gained quite a bit of weight. could this mean that I'm pregnant? I have been sexually active since with my new boyfriend for the past few months as well so there is no way to tell how far along I would be. I have just been panicking recently and need an outsiders opinion before I take further action.