Could I be pregnant??

My period was due last Friday but I didn't start until Saturday, when I did start it was light compared to my normal flow, it ended Sunday night. Now I can't keep any food down, I normally get sick about two-four times later in the evening or early morning. Other than that no other symptom except small bits of cramping every now and then. Just curious as to if I could be pregnant or coming down with more sinuses. Any advice or help would be greatly appreciated.