Sasuke knew he fucked up the moment he did it. He hadn't meant to send his family through a portal, but he had panicked. There was no way in hell he would allow Sakura to fight with their two-week-old daughter in her arms. That however did not mean that his instinctive choice was the better one. Could he have summoned Susanoo to protect them? If in the moment he had one more second to think, he might have done just that, but seeing Sakura unable to defend herself and about to be attacked, his instinct was to use his rinnegan. He sent his wife and daughter through a portal, Sakura was going to kill him when he brought her back.
Having sent his daughter and wife through portal was advantageous (though he reminded himself to not defend his action in any other form than, "I did it without thinking," because even he had to admit it had been extreme), he no longer had to worry about hurting either of them in the middle of the fight, or of the rogue ninja hurting them. He easily defeated the rogue ninja once his wife and daughter were no longer directly in harm's way.
The battle's end allowed him to pay attention to something he had pushed to the back of his mind. When he sent his wife and daughter through the portal, a lot of chakra had been used, he tells himself is due to the distance that had existed at that moment, but as he opens the portal to Kaguya's sand dimension he finds that there is no sign of Sakura or their daughter. He knows Sakura well enough to know she would not hide, he decides he likely sent her to the snow dimension, but again as he opens the portal he discovers there is no one there.
He knows there is no way he would have accidentally sent her to any of the other dimensions, but still through pure will power he opens one last portal, this time to the dimension Kaguya was sealed in. Once more he discovers no signs of his family.
Still he decides to try and stay calm, after all, panicking is why he accidentally sent them away, first things first he decides, go through the events what he did. It was early, he was keeping watch, Sarada woke up, and was fine, she became hungry, started to cry, which not only awoke Sakura but alerted the rogue ninja who were now tied to a tree. When Sakura was surrounded he thought of his family, and how he would not lose his family again, he thought of Itachi, and then they were gone.
Sasuke knew he fucked up the moment he sent his family through the portal, but until this very moment he did not realize how bad the incident was.
Sakura, wanted to kill her husband, sure she loved him and if there was such a thing as soul mates she was positive he was hers, but right now she wanted to kill the bastard. He had been over protective throughout the pregnancy, and while true she was still recovering, sending her through a portal to protect her and Sarada was more than slightly overboard especially without warning. At least she was still in the forest, but no matter how much she tried she could not hear any fighting nearby, and once she searched for signs of his chakra, she detected none.
Stranger still, her surrounding looked similar to where she had been, the placement of trees was the same, the height however revealed them to be shorter. Which could only mean her husband slipped her into a different dimension, not just a different a location.
Now as she looked to her left, she discovered that her darling husband had not just sent her and Sarada to another dimension, but through time, how did she know this? Her dead brother in law was standing right there, not even concealing the fact that he was staring. She had no time to worry about Itachi however as Sarada began to stir making that face that she and Sasuke had come associate with crying soon, this was not surprising, they had been attacked as Sakura was getting ready to feed her. Deciding that Sarada's hunger is the more pressing issue Sakura decides to ignore Itachi, after all he is not a threat. "You are Haruno Sakura."
"I am not," it was not a lie, after all she was Uchiha Sakura, and had been for some time now, "my daughter is hungry, could you give me some privacy?" Itachi left the immediate area but she was aware he was not far; he was giving her privacy while watching her closely. No denying he is Sasuke's brother, she mused but again she settled for ignoring Itachi instead of scolding him for the lack of privacy. After all, the main reason she wanted privacy was for a chance to think. She had no doubt Sasuke would come for them, but the problem is he likely had no idea where they were, and the longer her and Sarada were present, the more dangerous it would be for everyone.
A/N: So I am still pretty new to fanfiction so excuse any thing that makes this look funky if it does. So this story is gonna be a little weird with how chapters go and I figured I should explain here. Full chapters will not be published at once, instead parts of the chapter will be updated, then once that chapter is fully written I will eventually combine it into one full chapter, this is the first of those combinations, this was initially chapters 1 and 2, now its a combined prologue. As of now chapter one is complete I just haven't combined it all yet. Hopefully this isn't confusing to anyone, this is just one way to update the story more regularly, as the reader you'll get bits and pieces of the chapter before seeing it all together, and since I know how lazy I can be, writing out two-three pages at a time for one update as opposed to ten is much more comforting and makes it feel less forced (in my opinion). Anyway please enjoy.