why is brake light coming on intermittently? on 2004 BMW 325i

2 warning lights come on while driving and then turn off.

Asked by for the 2004 BMW 325i
Possible pad sensors or low fluid , both require visual check to verify. May be other causes also. Should have shop qualified to service BMW check it out.
Thanks so much. I did check brake fluid which is not low but pads are worn. Thanks for verifying my suspicions.