the last time i changed the oil in my car i found that it looked like water is getting in it, what could it be?

 

condensation. has the water also been magically falling from the sky? if so... you may have a problem.

 

guinness.

 

It could be something simple as condensation.
Also, there is the possibility that that a cracked rotor housing exists and it is leaking coolant into the oil. Keep an eye on the coolant reservoir for a drop in the level. It would be best to check it in the morning before you start the car.