2003 BMW 325 coolant

2003 BMW 325 120000 miles

Hi there. My coolant light came on two months ago. I took it to the mechanic. They flushed my system and pressure checked it. They said the pressure check was fine. My coolant light just came on again, and I checked the resovoir and it was empty. There was a puddle of coolant on the ground. I checked the oil for that "milkshake" look to the oil, and the oil seemed normal. It's synthetic oil and look like a yellow-brown color. Can you tell me a list of what it most likely could be? As a woman, I would like to know the possibilities before I head back to the mechanic. Also, the coolant seems to be leaking faster than before. Thank you!