Not feeling hungry?

I’m a bit over 15 weeks and once in a while I will feel not hungry- like at all. Yesterday for example I ate a bit in the morning(5am ish) and a little in the afternoon (2pm ish)but when it came to dinner time I just went to bed instead. I don’t know what’s wrong with me and it’s freaking me out- shouldn’t I be hungry all the time? What’s going on? Is this normal?