Bad After Taste?

Anyone else get a bad after taste every time after they eat?? It almost makes me feel nauseous...if I pop in a mint it helps until the mint is gone, then the bad taste is back! Brushing/mouthwash isn't effective either. I've had terrible all day sickness for most of the first trimester but it's let up the last few weeks and now I'm getting this awful taste. Any ideas on what could help?