no that scene was actually from ep 10x1, it was during the time the team were investigating all the corruption in the FBI. That scene happened after Booth was cleared of murder and released from jail, on the same night he and Brennan made love and I think that was when they conceived their son Hank Jr
As for Emily's pregnancy...I remember Hart Hanson mentioned that he initially wanted to hold off hooking Booth & Brennan together for as long as possible, but Emily's pregnancy ultimately "forced" them to finally take that leap and hook them up on the show, because they really had no other choice, with Emily being pregnant, they had to write her pregnancy into the show and make Brennan pregnant with Booth's baby. But I think even if Emily wasn't pregnant in real-life at the time, B&B still would've become an official couple eventually because it was inevitable...however it probably would've taken them even longer to hook up than they actually did in the series. B&B got together at just the right time in the series, when they were both finally ready to commit to each other and take their relationship to the next step
