it's early days

said when you think it is too soon to make a judgment about the likely result of something because a lot might still happen or change

当你认为对某事可能的结果做出判断还为时过早，因为很多事情仍有可能发生改变时，常会使用这个说法;言之过早、为时尚早、来日方长

Our progress has been fairly slow so far, but it's early days.

到目前为止我们的进度很缓慢，但来日方长。

I'm not sure if our book will be a success, it's early days yet.

我们这本书是否受欢迎，我没有把握&现在言之过早。