When and how did you find out there are actually 3 in there? Your first u/s showed twins, right?
At 5w5d we saw 3 "circles" on the screen, but two were very easily visible as having fetal poles, yolk sacs in etc and one was kind of off to the side and empty. The OB told me it was probably just a small bleed or something and said TWINS. Then 10 days later there was clearly 3 babies w/ 3 little heartbeats!
I lost my mind, actually. :) My DH was very calm and I burst into tears, started shaking really badly and then threw up. Then the OB started moving the wand around and saying "Okaayyyyyy" and I apparently said "For f***s sake, stop counting!!!" He laughed and said he was just measuring them. Then I had to apologize for cursing at my OB. :p Thankfully he was very understanding and said he has seen much worse. haha!