In general, you really shouldn't put much stock in the scores you see on company tests, no matter how good the company. No company test perfectly replicates the real GMAT (none really come all that close, in my opinion) and they're certainly not using real GMAT questions or the real scoring algorithm.
If you want a realistic assessment of your current level, the only way to get that is to take a GMATPrep test, or take the real GMAT, but if you got a 710 a month ago, you must have been around that level then. You've presumably gotten better since, if you've been studying, so I don't think you should be concerned. If your real test is in three weeks, you should be taking at least a couple of GMATPrep tests anyway, just to get comfortable with the test taking experience and with your pacing strategy, so you'll have good information soon from those tests.