The `Come and Get It` singer - who has an on/off relationship with Justin Bieber - is gearing up to celebrate her 21st birthday on July 22 but says she sometimes still feels like a teenager.
She told `ET Canada`: "I feel like sometimes I am 15 in my heart. You know, sometimes I just go in waves of being a child and being an adult. It`s awkward, I am growing up. I am just trying to figure out who I am."
But the `Spring Breakers` actress is looking forward to celebrating the milestone in Los Angeles next month and being legally able to drink alcohol.
She said: "I`m going to enjoy being 21, absolutely, of course.
"I am going to have a party. ... My family from Texas, my friends [and] my cousins are flying in. I will have some of my best friends in L.A."
Selena insists she has no regrets about anything she has done in her life or career to date, saying: "Everyone goes through things, the bad and the good, and at the end of the day, I don`t regret anything. It makes me who I am."
She has also learnt to accept that all of her actions are scrutinised because she is in the public eye. She said: "(Without it), I wouldn`t get to do what I love."