In Act 3 scene 4 capulet and lady capulet tell Paris that he can not meet Juliet today as she is upset and desterbed by Tybalts death and concidiring that he was killed by Romeo which they do not know it mackes her confused and upset.
So they talk about when they shall get married and paris wants to get married quickly but they diced to get married on Thursday instead but Juliet does not know that and they do not know that Juliet is already married