I wouldn't worry about it now. It's an awful time to try to get any grass to sprout and establish, unless it's blue grama or buffalo grass (and those wouldn't look right with the rest of your lawn).

Keep killing any weeds that crop up and put some seed down about September 1 or so. Don't use something like Patchmaster. Instead, get a good seed mix (and make sure it doesn't have any K31 or KY31 in it). After you put the seed down, water lightly 3 times a day for three weeks.

Adjust the watering schedule to account for any rain we might get. What you're trying to do is to keep the surface moist almost all of the time.

Even if you see a fair amount of grass come up, continue watering three times a day. The reason for that is because the mix you buy will probably have some rye, some tall fescue and some Kentucky bluegrass (KBG). Rye will germinate in a couple of days, fescue in a week or two and KBG in 3 weeks or so.

Once the three weeks are up, cut back to once a day, but water a little longer when you do water until it cools off enough and/or we're getting enough rain that the soil is staying fairly moist in the top inch or two.