IUD pregnancy thoughts?

Been having cramps a lot lately. My period started on the 17th and ended on the 20th And was extremely light and more pinkish than normal. Lost of appetite lately and Feeling a little nausea today. I’m currently hungry but thinking about food makes me want to puke. I’ve had the skyla IUD since 04/2016. Took a pregnancy test this morning came back negative. Thoughts? Concerns ?