This is from Lady Macbeth's soliloquy at the very beginning of Act II, scene ii. Macbeth had left at the ending of the previous scene to carry out Duncan's murder. Lady Macbeth's comments here are derived from the tension she feels as she awaits her husband's return. In fact, she questions in this soliloquy whether or not Macbeth has been able to carry out the murder of whether he was interrupted in his task. We see the beginnings of the turmoil swirling within both Macbeth and Lady Macbeth in this soliloquy and in the scene as a whole.

These lines that Lady Macbeth speaks are not an aside.  I suppose that means that they must be a soliloquy, although a short one.

An aside consists of lines that are spoken directly to the audience while there are other actors on the stage.  We are meant to believe that the other actors cannot hear them.

In this scene, Lady Macbeth is the only one on stage when she speaks these words.  Soon after she speaks the words, Macbeth enters.  But when she is actually speaking, he is not on stage.  Therefore, it cannot be an aside.