What happens if you have human contact to a robins nest,with eggs URGENT

A robin made its nest close to my house door we took it off then figured there was 4 blue eggs in it we put it by a tree , and some bread crumbs so the robin can see it. Later that day the robin hasn't found its nest by my tree what do I do there is still eggs in it?

If you are going to move a robins nest, you can only move it at very small increments , a couple of feet at a time.You could move it as often as 4 or5 times a day. A problem is that even a small movement may then present the nest as belonging to someone else. The one moved straight away to the tree will certainly be overlooked. It isn't if you had contact that panics the birds. Its if they feel they are no longer safe. Move the nest back to near where it was.
You really don't have much time in this weather. The eggs are kept from getting to cold. If this happens they die. The female doesn't begin setting until she has laid her full compliment of eggs. then she sets and they all hatch at nearly the same time. Your feeding will have no impact on the birds. Even though they are close to the door, they will soon learn not to attack you. You could get a ring side seat at the hatching and rearing of the young. You may consider moving idt back to its original spot. She may even use it for the next clutch. If the eggs are dead and she lays new ones, she will kick out the dead ones after a while. Live and learn.