Playing games with my head?

So Tuesday when I went to the bathroom there was a kinda brown discharge on the toilet paper.. and it has been like that ever since. There is only a little bit on the pad but not heavy like a period.. my period is due tomorrow. I woke up very nausea this morning.. I also have a headache. I feel like I am hungry but when I go to get something to eat my belly gets upset. Could I be pregnant or my mind playing games on me :/ could I just be getting my period or could I be pregnant