In Romeo and Juliet, what does Juliet not fear before drinking the potion?

I suppose that you could list far more things that Juliet is not worried about than you could list things that she is worried about. She is very concerned about her own life. She does fear that it could be real poison, but Juliet spends the majority of her time talking about the physical and mental trauma that waking up too early in the tomb might cause her. What Juliet is clearly not worried about is whether or not Romeo will show up at all. She is fully confident that Romeo will be there. She fears about waking up before he comes, and she fears she might suffocate to death if he is late, but it never crosses her mind that Romeo might not come at all. Her love for him is so deep that she has every confidence in the world that he will know the plan and be there to help her out of the tomb.

Before drinking Friar Laurence's potion, Juliet lists many fears that she has. She fears that the potion might kill her, and that she might wake up in the tomb before Romeo can get to her. She fears that she will suffocate in the tomb if Romeo takes too long to arrive. She fears that she will be alone with the ghosts of her dead relatives, and she fears that she might go mad.
However, at the beginning of her soliloquy, Juliet says:

"Shall I be married then to-morrow morning?No, no: this shall forbid it: lie thou there."

From this quotation we can infer that the one outcome Juliet does not seem to fear is her arranged marriage to Paris. The "this" and the "thou" that she refers to is the dagger which she lays down beside her. In other words, if the potion should fail, Juliet is determined to kill herself with the dagger. Thus, she will not, in any circumstance, have to marry Paris. This is the one outcome she refuses to countenance, and thus the one outcome that she does not fear.

In act four, scene three, Juliet holds the vial in her hand containing Friar Lawrence's sleeping potion that will make it seem like she is dead shortly after she drinks it. While Juliet holds the vial, she begins contemplating what will happen once she drinks the potion. Juliet initially fears that Friar Lawrence may have purposely given her poison instead of a sleeping potion to prevent her from marrying Paris because he has already married her to Romeo. Juliet then fears that she will wake up in the Capulet tomb surrounded by the remains of her ancestors before Romeo arrives. Juliet also fears that waking up in her family's tomb will drive her insane to the point that she would use "some great kinsman’s bone" to bash her own brains out.
Despite Juliet's anxiety about drinking Friar Lawrence's sleeping potion, she does not fear the implications of what will happen to her and Romeo if the plan works out. Juliet is completely concerned with what will happen if the potion harms her or if Romeo does not arrive. She is unconcerned with how society will treat her and Romeo outside of Verona. Juliet does not fear what life will be like in a foreign country and does not worry about what obstacles she will face in the future after waking up from the potion.