Loss of Appetite?

So I'm going to be 17 weeks tomorrow, and I've had this feeling for the last couple of days. Up until then, I could eat like a pig (and I actually LOST 3 pounds which I don't get at all), but now I was really hungry for lunch and hadn't eaten in 4-5 hours. I made myself some pasta and buttered toast, ate the two slices of toast I had and maybe 1/3 of the pasta when before I was running for seconds. Has anyone else experienced being unable to eat enough or as much? I know increased appetite is a 2nd trimester "symptom", but it's SO not happening with me.