Not wanting to disturb a bird's nest

Hello, I'd be very pleased of some advice please.

We are about to embark on a small building project which will require us to take down and replace an old 6' high garden fence covered in ivy.

Our neighbours think that there may be an active birds nest in the ivy, and although there was some years ago, we don't think that there has been one for a couple of years and we cannot see one.

Obviously, we don't want to disturb any active bird's nest and we are aware that we shouldn't do so in terms of the law.

Does anyone know of someone who could take a look at the fence and ivy as a recognised independent verifier to determine whether there is or is not a currently active nest, thereby enabling us to build now or determining that we will need to wait to make our small alteration in September, -  the build for quite an urgent need for us?

We would be very grateful for any and all advice. We are in central Cambridge.