Call and get an appointment. Check your insurance benefits, sometimes the evaluation is covered when thearpy is not, and you could benefit from having that evaluation to give to the ECI theripist. By age two, he should have 50 to 100 words and be putting two together in a simple sentence. At two, you should not expect his speech to be without errors and substitutions, as these are expected at this age.
If you can afford it, you may want to supplement his speech therapy privately. ECI is the preschool version of IDEA, that is how it is funded. IDEA is only required to make your child "functional" in the classroom, not to maximize your child's development. That is not to say that if your child has very mild issues, that this might not be enough, but no parent should expect it to be, and should know that they may have to make some hard choices. Early intervention can make all the difference in the world, and sometimes, it can be more important to invest in early speech therapy, then to start saving for college.
Once he turns 3, the local school district is responsible for his services, if his speech issues are severe enough to qualify. He can qualify for speech only through the school. Again, they are obligated to serve him if he qualifies for speech services, but, they are not mandated to maximize his potential, which is what you will want as his parents.
I would see what you can swing, and try to get the private evaluation paid for, so that you do not know less than the state agency, or the school, about what your son needs. You might be able to work out a payment schedule with a therapist, maybe going less often and doing more homework...but I would definitely find out if he needs more than ECI will provide, and then find a way to get it for him.
Good luck,
M.