Why am I sick?!

Amanda
So I'm 15 weeks 5 days Preggo and feeling pretty good overall. But....... Some days I start out good then all of the sudden I feel like garbage. 😖 I can't tell if I'm dehydrated or not eating enough.... Anyone else feel this way? Or if I sit too long I feel gross... But I stand up and walk around a it and I'm good for a bit