I don't breed, but just from reading posts from those who do, it seems the majority of the time a females first clutch is not fertile, but it wouldn't be a surprise if they were. Someone else can add more to this.
I had a first time breeder last year that only laid one clutch and both eggs were fertile. anothers first two clutches were infertile. I can't give you any kind of percentage rate though because this will only be my second season.