This question is missing a lot of details which might make it definitely answerable. Some of the required details will need more time to find out. Here is some info to help with your decision.
Infections
A beer or cider can be ruined if fermentation stalls and bacterial growth takes over. If this happens the brew will taste bad. This article provides a detailed overview about infections and what they mean. Infections are not the end of the world. People brewed cider for thousands of years without doing anything to specifically prevent infections. If you suspect it is infected, AND it tastes bad AFTER fermentation finishes, throw it away.
I then found a leak from my new fermentation bucket, the supplier has sent me a new one but I would like to nurse this through and get it in the pressure barrel in four days time.
This could be a route for infections to get into your cider, but maybe you lucked out. Time will tell.
Is it worth saving?
I have four fermentors, and fermentor space is not a limiting factor for me. I also brew more than I can drink, so I value variety over quantity. My personal setup means that any suspect brew is always worth saving unless I am certain it has gone bad.
If you only have a single fermentor, your situation is a little different. It is definitely worth giving this beer a little more time, until you know for sure it is bad. Don't rush into a decision.