Yeah, sadly, I agree with PPs that May is not such a long time to wait for an initial appointment with a dev ped.
Concurrently, you could pursue OT or speech therapies. I was able to get my DS evaluated at a therapy center and started on his therapies before he saw the dev ped, and I end up using the dev ped THEY recommended as the best one in town. They should know, right?
My son's DX is essentially useless in terms of getting better access to services (he has ADHD with heightened anxiety, the school district couldn't care less), but I'm still not sorry I got it. Knowing that it's not ASD makes a difference in how I approach the behavioral problems and my long-term plan for his education. And an autism spectrum DX, even one that is complete and utter bullpoopie, may well get your son access to school-based services. At this point, I wouldn't care if they DXed my child with rabies if it got the school to provide some freaking help!