Well, I'm waiting for Viz to confirm this bc MP and MS have pretty different interpretations-- but it seems she chased after him and traveled with him for a bit. I'm thinking she broke him down and they got married in some far off village at the justice of the peace or something. Then she got knocked up and she gave birth at a nearby hideout where Karin helped deliver the baby. Then she returned home with the baby while Sasuke continued the mission.
So, I suppose they wouldn't have any wedding pics under those circumstances.