Dress alterations -how soon to do them?

I just bought my dress for March 2023 wedding. I know for sure it will need a major hem, shoulders/bust brought up/adjusted, and probably let out a little bit. I'm really short and my torso is shorter, hence the hem and shortened shoulder/bust area, and my dress almost zips/clips all the way up (it's a tight squeeze and doesnt quite clip all the way) so maybe 1 inch let out I would assume. When I bought it the lady asked my normal pants size and thats the size she wrote down for me to order. I'm worried they won't be able to let it out. I recently lost 15lbs without much effort, so it's possible I'll continue to lose weight so I don't want to get it altered too early just in case. But my weight loss has stopped for the past 1-2 months so I may not lose anymore. I'm worried the dress won't fit and I don't want to wait too long and they not be able to get it altered in time. Dress was bought from David's Bridal and they have me coming in for alterations 7 weeks prior to wedding --too soon, too late, or just about right in terms of timing my alterations fitting?