The gorgeous Palm Beach native visited Sheen on the set of a Hanes commercial he was filming with Michael Jordan outside LA, and took pregnancy tests in his trailer, says one insider. "She would throw them out in the garbage on set and place them right on top . . . everyone could see the sticks," said our spy, who added Mueller would walk around showing off her "enormous" yellow diamond ring to the crew.No word on whether the pregnancy tests boasted a minus sign or the plus sign of doom, but one can only hope the former. At this point, Sheen's blood stream looks a lot like the East River — full of flotsam, discarded bottles of Jack, the occasional hypodermic needle, a dead hooker or two. Really it's lucky that the first kids were born with only one head and didn't have hands for feet. Let's not tempt fate here. We also can't imagine what Hanes was thinking signing up Charlie Sheen, but we're looking forward to their new spring ad campaign: "Look whose toxic, prostitute-penetrating bulge we have our Hanes on now!"