Morning Sickness?!?

I think my body is confused! So, I made it through the first trimester with relatively no morning sickness. There were a few weeks in there that I felt pretty nauseous at times and had to make sure my stomach was never empty, but that was it. Really nothing to complain about. Actually, I was feeling pretty guilty because my sister, sister-in-law, and some of my friends had horrible morning sickness during their pregnancies and I kind of felt like I got off easy. BUT... now, I'm not so sure. Since I've entered the second trimester, I've been sick (like... throwing up sick) three different times. One of those times happened to be this morning. What is going on?! Even as I write this, I'm not feeling so great... oh, the joys of pregnancy! But, let me say - it is so worth it and I'm not complaining!! :)