Why can't you just start your lawn from seed now and use a pre-emergent to prevent weeds in about a month or so? Well....
That new lawn needs time to establish and those roots would not be happy with a dose of pre-emergent so soon after seeding. If you want to learn more about pre-emergents and seeding and what options you have in your lawn, check out this video - https://youtu.be/J2PLTQXWp9g
