Semi-Final (SF) status is based only on your PSAT score and the state you reside in. In other words for example, a 218 PSAT score will qualify you for SF in most states but not say in MA where the cut off scores are usually above 220. So with a 226 you will qualify in any state, based on previous years statistics (the highest it has been is about 224 or 225 that I have seen but that was some time back).
You can wait until you get your SF notification and then do the needful. You do not need to send the scores now or really do anything now. As you have already taken the SAT, if your scores are above say 2050, you do not need to take the SAT again for NMF purposes. You may however want to re-take it to improve your score for colleges etc and send the best score to colleges and NMSC. In other words, if you are happy with your SAT score when you get them, there is no need to take it again for NMF. I have told that SAT cut off for making it from semi finalist to finalist is about 1950 but these are anecdotal numbers, so to me 2050 is a very safe number. Obviously the higher the number the better, so make a decision if you want to retake the SAT once you get your scores.
So to answer your question, use your credits elsewhere. If you are happy with the scores from this test, report them to NMSC in Sept 2010. If you are not happy with the scores from this test, take the SAT again and report the best score.