She made her international debut in 2013, representing her country at the 2013, 2014, 2015 World Junior Championships, and 2014 Summer Youth Olympics.

She won the gold medal at the 2015 European Junior Championships in the girls' singles event, also helping her team take the bronze.

In 2018, Blichfeldt reached the semi-finals of the European Championships, but was stopped by the host player and 2016 Olympic gold medallist Carolina Marín, thus having to settle for a bronze medal.

At the same year, she won her first Super 100 title at the Dutch Open, when she defeated Qi Xuefei with a score of 21–16, 21–18.

In 2019, Blichfeldt won the Spain Masters, a Super 300 tournament, by beating compatriot Line Kjærsfeldt with a score of 21–14, 21–14 in the final.