After hastening to Friar Laurence in her despair, Juliet talks of leaping from the battlements, so Friar Laurence tella her, "I do spy a kind of hope." He encourages Juliet to consent to marry Paris. And so, Juliet returns home and apologizes to Lord Capulet. When she says, "Henceforward I am ever ruled by you."
Hearing his daughter's apology, Lord Capulet is so satisfied that he calls a servant,
Send for the County, go tell him of this.
I'll have this knot knit up tomorrow morning. (4.2.25)
and he advances the day of the wedding, sending for Paris to tell him that he and Juliet can marry on Wednesday, rather than Thursday. Hearing this, Lady Capulet says there is time enough and they can wait until Thursday, but Lord Capulet insists, "We'll to church tomorrow." He is not going to give Juliet an opportunity to change her mind after her conciliatory words. Now, Juliet can do nothing other than follow the Friar's advice if she wishes to eschew marrying Paris.