If you are at peak of your preparation and in a “maintenance” phase and are able
not to be distracted by other things (exams) going on in your life, I would just take it.
If you can benefit of a few weeks extra of preparation (while studying and potentially being distracted by finals) I would take the opportunity offered and move it.
Either way I wouldn’t worry about it too much especially if you are a strong performer. If you are a borderline one your concern might be legitimate and Considerations I made above are important.
As a curiosity, did you mentioned this to HR and then they offered or they proactively offered it to you?
hope this helps,