Nothing to worry except that your time gets wasted.
If you score very high in one area (usually objective types lets say reading or listening) and somewhat low in another (usually subjective types like writing or speaking), then they hold back the result for a second round of review by another set of examiners.
The second review might actually increase your score by .5 or 1 but it depends. The result gets delayed by 3-4 weeks and is usually declared just before their next examination results.
I scored 9 in reading and my result was with held, finally when the result came I was CLB-9 so I suspect I was originally given 6.5 in another area which was bumped up to 7 in the second round of review.
Wish you all the Best.