When to buy a wedding dress if losing weight?

Good afternoon, I'm curious about a specific scenario related to wedding planning. I'm currently in the process of shedding some pounds before my big day, and I'm wondering about the timing of purchasing my wedding dress. Is it advisable to wait until I've reached my desired weight before shopping for the gown, or is there a strategy to ensure the dress still fits perfectly once I've reached my goal? I'd appreciate any insights or advice you may have on this matter. Thank you in advance for your help.