FireWolf,
When you report your GMAT scores, the schools will receive all of your test scores from the last 5 years. This means that if you have already taken the GMAT twice, you cannot cherry pick which score to send--the school will receive both scores.
Technically you could probably send in your current score now, and if you retake and do better, you can try to send the scores again as an update. However, this would depend on the school accepting an updated score even after you've submitted your application. You should check if this is possible.
Nevertheless, there is always the risk that you may not do as well if you retake the GMAT. Of course, if you do not do well on the retake, you could take the GMAT a third time! That is something only you can assess. However, a 700 score is nothing to sneeze at.