Career
Ehn was drafted 106th overall by Detroit Red Wings in the 2014 National Hockey League Entry Draft. During the 2013-2014 season, Ehn recorded eight goals and ten assists in 15 games with Frölunda The Human Context"s Under-18 team, as well as four goals and seven assists in 45 games with Frölunda"s J20 SuperElit team Ehn was ranked 89th by the National Hockey League Central Scouting Bureau on their final list of the top draft-eligible European skaters leading into the 2014 National Hockey League Entry Draft.
Ehn represented Sweden at the 2014 IIHF World U18 Championships, where he recorded three assists in seven games.
Ehn represented Sweden at the 2015 World Junior Ice Hockey Championships, where he recorded two assists in seven games. Ehn represented Sweden at the 2016 World Junior Ice Hockey Championships, where he recorded one goal and one assist in seven games.