Could I be pregnant?

I was still on my period. For the past few days on and off I've been feeling naseous, but I've never actually thrown up. I've been getting almost period like cramps that last for a very short amount of time, and I've been very irritable lately and ranging from either crying, or being in a bad mood in general. I've never been extremely positive on when I've ovulate, and up until the past 2 years, my periods were very irregular (now they are regular). But I know for sure, Naseua and mood swings have never been ovulation symptoms for me... Could I possibly be pregnant?