How far along are you? Most ftm don't start to show til around 20w or later. And losing weight in the first trimester is completely normal, second tri as well since you're body is still getting used to the hormones you might not want to eat or might still be throwing up. For me I had horrible headaches that kept me from eating lol. Just make sure you take your vitamins and stay hydrated, try to eat small snacks throughout the day.