Yes that is very normal. I remember when I was at your week, I was craving for the food of an eat-all-you-can resto. My mouth was watering when I saw all the food but when I was about to taste what's on my plate, I lost my apetite. I was able to eat maki and halo-halo only 😔 Anyway, just continue eating whatever your stomach can take. On your 2nd tri, your appetite will be backed 🙂