Sam really didn't know what to say or do. He had gone over The Plan in his head over and over again, because - of course - with Sam Winchester, there always had to be some kind of plan. Step one: find the girl who claimed to be their child. Step two: make sure that she was their child. Step three: ...panic. Hey, no one ever said that The Plan had to be a good one.
Long fingers drummed at the wheel of his truck; it was a nervous driving habit, one that Sam had tried to stifle on many occasions, but that nervous drumming of his had yet to budge. He didn't much care that it was seeping through in his mannerisms now - Ruby was just as, if not even more anxious about this as he was - so it wasn't as though he had anything to hide. Doing so would have been pointless. Furthermore, worrying over Ruby noticing him worrying would only take away from all the extra worrying that he needed to be doing about meeting this 'Emily'. Instead, Sam focused on driving, going over The Poorly Constructed Plan repeatedly (see also: worrying) until he pulled up to the location that the three of them had agreed to meet.
Purposefully, Sam steered the truck onto the other side of the road. Before Ruby could climb out, Sam instructed her (knowing that she wouldn't listen) to stay in the truck just long enough for him to be sure that they weren't being set up.
He set out as soon as the words left him. He knew it wouldn't be long before Ruby stubbornly followed him and Sam would be damned if he let anything get the drop on them with his pregnant wife out in the open and entirely vulnerable to being attacked. Ruby might have been able to handle herself in a fight, but that wasn't gonna stop a cocky demon from aiming a low kick at her stomach, was it?
He didn't want to think about it, nor did he want to take any risks. Quickly, Sam jogged across the street, desperately scouring the area for any sign of a set-up.
He only found the girl.
Sam didn't approach her right away. Instead, he sort of stood to the side, looking as though he were waiting for Lucifer himself to jump out from behind the little girl with a mighty, "SURPRISE!"