My guts telling me something isn't right

I've been with my husband for a very long time. We've had our ups and downs and he's cheated in the past. I thought we had worked through everything because the last few years have been great. But for the past month I've noticed his behavior is different. Hes always on his phone supposedly playing a game. And he leaves and stays gone all day into the night saying he's working but are having financial problems....... I've been a Lil nosy and haven't found anything. But my gut Is telling me something isn't adding up.