score:4
Both Denmark and Sweden are in the Schengen area, so crossing the border is not leaving and re-entering Schengen. There will be no problem at all going back to Denmark. There may be a problem going to Sweden.
A day trip across a nearby border is normally just a minor adjustment to the travel plans. Make sure to bring your documents for the border crossing, and to bring only enough luggage for a day trip.
The way Schengen is supposed to work, there would be only random spot checks at the border, no systematic checks. Since the 2015 refugee situation, border checks have become more frequent again, with an element of racial profiling and a geographical bias. Going southwards is less likely to be checked than going northwards. But those would not be immigration checks where visa are stamped, they would check that you already have an entry stamp.
Upvote:1
Technically, by going to Denmark to Sweden, you will not be crossing any border of the Schengen Area. There should not even be a border check. By travelling back to Denmark you would not be entering Schengen again, since you never left it.
If I was you, I would do that, but as a citizen of a Schengen country, I speak as someone from the other side of the fence. Let us know.