Is it possible to ovulate early?


Last night I felt a lot of lower abdomen cramping on the right side as i usually feel when i am ovulating, but this time it seemed to me that it was a lot earlier than normal.

But Glow says that i should be ovulating tomorrow (cycle day 13).

I'm confused šŸ˜‚

Is it possible to ovulate earlier than expected, or was it my intestines tricking me?