I have painless nausea took a pregnancy test and came out negative. what could it be?

Many causes: Nausea is very likely in other GI conditions such as simple stomach virus, gallstones, pancreas problems, liver problems, gastritis, reflux, and infections/inflammation in the stomach. If your cycle is late- you may just be very early and that can cause a negative preganacy test. If this is a persistent problem - go see your doctor. Good luck :).