4 unit blood transfusion during 34-week pregnancy. What will be the next schedule?Is delivery will occur early?

Aritra, NO ONE online can possibly answer this, not even 100 doctors.
You give absolutely no details or background anyway.
ASK YOUR DOCTOR!
Is there a reason you haven't? Is this about Rh factor? Anemia?

As a labor and delivery nurse I can't even attempt to answer this question with such little information.

Why are you getting a transfusion?

Why are you not asking your doctor these questions? Your doctor knows your medical history and why you're getting transfusions, and what's going on. We have no idea and your very limited info has not given us a clue as to why you're having transfusions or how it will effect the delivery date.

These are questions your doctor should be answering, and obviously he/she isn't answering them well enough for you to understand, or you're not asking enough questions. So start asking the one person that can actually give you answers. This is too important to leave to the internet.