I normally don't eat much & lately I've been getting sudden hunger & if I don't eat within minutes I get nauseas & my body shakes. Pregnancy or diabetes?

Either/ both. Sounds like you should be tested for both! please don't let this go on for long! eat smaller but frequent meals if it happens a lot, and get tested for diabetes (more than a finger check) and pregnancy. High glucose levels have to be controlled, and low ones can be life-threatening.