The spreading of a good quality compost is always recommended to inject organic matter into the soil which, when carried out as a spring program, will encourage moisture retention, worm production, and good overall soil which grass seed will grow much better.

Pre-emergent is, what it means....a means to prevent the germination of seeds which come from weeds, et al, It is usually applied at a specified time when the weeds are going to seed.
Pre-emergent then is a weed seed killer. It is therefore, also a killer of any kind of seed---including grass.
I believe a minimum time of interval between application of the pre-emergent and seeding a lawn, is about 6 weeks.
This is the reason why the pre-emergent is applied when the weeds are sprouting their seeds which will deny germination of the vast majority ---but not all--of them.

The company that did the application of the pre-emergent should have known when you can safely carry out a seeding program.
Give them a call.

They said not to plant until fall... :(
But they don't have to live with muddy dog paws every time it rains! I need some grass! :P

I tried to dig into the clay to add the clay breaker but even with the clay being wet, the shovel goes down about an inch when I jump on it. Totally pointless. I was hoping I could amend the soil & it would still be soft enough to plant SOMETHING in over the summer.

SOO, I spread the clay breaker (really just a high-organic-content soil mixture) with some of my compost on the bare spots. I'll just overseed it with a LOT of seed in a few weeks and hope that 10% or so of it manages to root itself in the new dirt. Even if it just lives for a little while I can do it again in a month or so, adding more soil & compost each time. Not exactly ideal, but it'll have to do!

Thanks!

Suggest you also spray shampoo on your lawn at a rate of about 3 oz per 1k sqft every month until fall. Make sure its just shampoo, not conditioner or anything fancy. The key ingredient in it is sodium laureth sulfate. I also live in NC, and also have clay soil. This helped out a lot. Measure your progress each month by stabbing a scredriver in the ground. It should continue to get easier as you go...

TruGreen did that to my moms lawn. Sprayed Barricade in july!
To loosed clay soil there is a product called Earth Right. In no way am I connected to it.

I tried Earth Right AND Sodium Laureth Sulfate (for which I paid a fortune, rather than using shampoo- duh!) 3 or 4 years ago when we moved here and neither of them even TOUCHED the hardness of the clay. I don't think I could get a screwdriver into the ground when it's dry unless I used a hammer drill! :P
We're building a new house so we'll be moving in the fall, so my only concern right now is to grow something green to keep the dust & mud to a minimum until then!