I’m afraid that your pregnancy and the noise on the street is not relevant. You entered into a three-year tenancy and you are bound under the terms of that tenancy for 3 years or until the landlord gets another tenant. However if you have found the tenant, the landlord cannot unreasonably refuse to take on the new tenant. So therefore it depends why he was not taking on new talent and whether they were not financially viable .
If you want to leave, you can tell the agent that you intend to leave in one months time and that if the landlord pursues you for the balance of the rent, you will defend the action on the basis that you have found 2 replacement tenants and your landlord has refused to consider either.
You are then in the hands of the court.
However before doing anything you need to ask the agency on what basis these replacement tenants have been turned down. If they refuse to tell you, make sure that you have it in writing because that would support a defence to an action by the landlord
Thank you for letting me assist you with your legal question. I am glad that I was able to help.
I am not certain whether that answers the question for you or not, but I am happy to answer any specific points arising from this.
It will be my pleasure to help you again either further with this or any future questions you have