Hi TJ and welcome to the forums!
You have certainly come to the right place as you will find all you need to know on budgie care here.
The information on the several articles and sticky threads at the top of each section of the forums will be extremely useful.
If you don't mind, I will start by asking a few questions:
Is this your first time breeding budgies?
Are you relatively new to the species?
How old are your budgies and have they been properly conditioned to breed?
Before taking the breeding route and in order to do so more safely, a person should have a very good grasp of the species (this comes with real life experience in budgie ownership) and to do the required research into the subject.
The decision to breed comes with a whole lot of responsibility and commitment, the lives of the breeding pair(s) and the chicks are depending on you and the response you give if/when faced with adversity.
Things like being able to tell if your breeding pair is in good health and top physical condition to go through breeding; when a hen is expecting an egg or if she is showing the first signs of being egg bound; when a chick is having developmental problems, not being fed or showing signs of dehydration;
when there is aggression, abandonment and neglect of the chicks and it's solely up to you to feed and raise the chicks. The ability to detect early on and solve these issues can truly make a difference on the outcome of your breeding journey.
Please read this link: A heartfelt plea to forum members new and old
As for the current problem you are experiencing and from your description it does seem that your hen has abandoned her clutch and at this point if she hasn't been incubating the eggs for the past few days, then the chances for any egg to hatch is slim to none.
There are a number of factors that can contribute to clutch abandonment (this can happen when the pair isn't on a stable and stress free environment, when the hen perceives a potential threat on her safety for example when there is a night fright). In this particular case it was most likely due to your 4 day absence.
It's never advisable nor recommended to leave a breeding pair unattended for so long.
Even by placing extra food and water, it's not guaranteed that it will be sufficient, especially for a breeding pair who eats larger quantities of food.
I'm not even mentioning potential accidents where the water or food could be dumped onto the cage's floor.
Your breeding pair, especially your female has determined the conditions not safe nor ideal to carry on with breeding and she abandoned her eggs as a consequence.
At this point, you can candle the eggs to check for life. If they are no longer viable, then discarding the eggs, removing the nest box an giving your pair the required time to rest from their fruitless breeding attempt will be the best thing to do.
In the meantime you can take full advantage of the information found here so that you are better prepared if you choose to later on allow your pair to breed. It's extremely important to plan ahead when breeding is involved because the pair and the eggs/chicks need the full support from their owners and this is done on a daily basis to provide everything they need in order to succeed.