Could i be pregnant!!!!!!!!!!!!!!!

i have an iud and i have had it almost 3 years and i have never had it make me sick or anything .. but i havent had a period in 3 years ..so this is what is going own with me . in the after noons i am getting were for no reason i get tired to were i have to take a nap , i am gaining weigh .. but yesterday when i woke up i was feelin really sick to my tummy but i never did get sick it went away . so we went and ate lunch well there i ate like 2 bites and then the feeling came back i didnt thank about it. so i keep eating but it didnt go away i got sick and later that day while shoppin i ws walkin and for no reason i got sick .. got this be a sing that i am prego or cold i just be gettin sick . does anyone no anything about iuds ? please help me adn god bless