Are Nausea, Excessive Hunger And Intermittent Diarrhea Signs Of Pregnancy?

I am usually always right on time like clock work with my period I was due for one jan3 and still three days later nothing. I have been feeling like I want to throw up lately it's been going on for three weeks now I eat and instantly im hungry again I've had diarreah and every once in a while cramps on my left side then they go away and still no period could I be pregnant? Every time I think I am im not don't want to get my hopes up