In this interview, Minnesota author Charles Baxter explains how he knows he is on a good streak:

I work during the morning. I pace; I stare out the window. I sit with my head in my hands. If I can feel myself breaking out into a sweat, particularly from my underarms, and if I give off a noticeable body odor that even I can smell, I know the writing is going well…

If it feels too easy, maybe give your last few pages another look.