For The Past 3 Days I've Had Nausia That Only

For the past 3 days i've had nausia that only happens in the afternoon and disappears in a few hours. i havent actually thrown up, but i get queezy. Ive also had a slight fever, chills and mood swings. I just finished my period last friday. Is it possible that i could be pregnant? Ive been on the pill for 3 years now and take it every morning so Im very carful with it. what else could cause these simptoms?