The oil light came on in the car. The oil was just changed a month ago. I also checked the level with the dip stick and it seems to be fine. Any idea what may be wrong?

Is there an oil level sensor that may have gone bad? Or popped off?

I did recently have my O2 sensors changed. Could they have disconnected the oil level sensor by mistake?

 

The oil level sensor is near by the O2 sensor on driver side header.

If they changed the bank1 sensor1, then it is possible that they messed it up.