Did I apply the direct aggressive and assertive communication style correct in this conflcit?

Did I apply the direct aggressive and assertive communication style correct in this conflcit?

Once I borrowed a pen from my classmate, but I forgot to return. One week later, she came to ask me: "Why you steal my pen?" And then I explained that I forgot to return the pen to you and I didn't keep the pen on purpose or consciously. It is