I am not an expert on cockatiels, but I will try to help.
First off, how old are your birds? What kind of diet are they eating? Also, do you have any previous experience raising baby parrots or other birds?
It is a good idea to consider carefully before allowing parrots to breed. As a first time breeder, you will need to do plenty of research and buy supplies in advance to make sure that both you and your birds are ready for babies. A lot can go wrong so you want to be well-prepared. Breeding is a big responsibility.
If your birds are pets and you are not prepared for baby parrots, it may be better to simply remove any eggs as soon as you notice them and replace the real eggs with dummy eggs. Or boil the eggs, mark them so you can tell them apart from freshly laid eggs and put them back in the nest. Also, it is good to know that hormonal behavior, like egg-laying can be discouraged by adjusting the parrot's environment in various ways. With the right changes, your birds can be encouraged to not breed unless you want them to.
If you DO want to breed cockatiels, I recommend reading as much as you can right now. Ideally, you should be getting ready before the birds are ready. Fortunately, there are many knowledgeable people here that can help you find the answers you need.
Speaking of which, back to your question - you mentioned it has been a week already. Is that from when you found the eggs? How long since the last egg was laid? Also, where were the eggs laid - do they have a nestbox?