Obretenova took up the sport in October 2015.[2] In 2017, competing among girls born in 2005–2006, she won silver in the All-Around, silver with rope and ball and bronze with hoop at the International Tournament Ness-Ziona.[3]
In 2019 she took 5th place among pre-juniors at the Bulgarian Championships.[4] In September 2020 she won gold in the All-Around in the junior category at nationals, in front of Dayana Dimitrova and Antonia Marinova, also claiming the title with clubs.[5]
She became age eligible for senior competitions in 2023, when she won gold at the national club championships as a member of Iliana along Andrea Gyoreva, Karina Petrova, Emona Tsenova, Dara Stoyanova, Magdalena Valkova, Slaveya Donova, Victoria Evtimov, Monika Mladenova, Raya Bozhilova, Tatyana Volozhanina, Stiliana Nikolova and Alexandra Petrova.[6] In July 2024 she was included into the selection process for the Bulgarian group for the 2025-2028 cycle.[7]
In June 2025 (after part of the gymnasts that competed in Paris retired) she was called up to enter the national senior group, debuting at the World Cup in Cluj-Napoca where Bulgaria placed 5th overall, 8th with 3 balls & 2 hoops and won bronze with 5 ribbons.[8][9][10] In August she was selected for the World Championships in Rio de Janeiro along Danaya Atanasova, Sofia Ivanova, Alina Kolomiets and Rachel Stoyanov.[11] There they took 6th place in the All-Around (having had a drop in their mixed routine), winning silver in the team event along Eva Brezalieva and Stiliana Nikolova.[12]
In 2026, Obretenova, Magdalina Minevska and Sofia Ivanova remained in the group together with newcomers Raya Bozhilova and Magdalena Valkova. On March 28-30, they competed at Sofia World Cup, and won bronze medal in all-around.[13][14] In Baku they were 8th in the All-Around, 12th with 5 balls and took bronze with 3 hoops & 4 clubs.[15][16][17][18]
Bulgaria 
Bulgaria 