Don't worry. It is the day length. It is after your winter's solstice so light period is increasing vis a vis daily dark period so that will stimulate the hormones to start ovulation.
I know people tout squatting as a sign of imminent lay but I don't put much stock in it.
I had a few hens that would squat years ago before I had a rooster running with each flock but haven't seen a squat in a long time with dozens of hens and 20+ eggs a day.
Squatting is a desire to breed, not that ovulation is imminent.
When the body prepares to ovulate, the space between the pelvic bones widens to allow an egg to pass. Check the distance between the pointy pelvic bones. If it is less than two fingers' width, an egg can't pass. If it is more than two fingers' width, laying is likely imminent.