Which Scores To Send?

Okay, so today my ACT scores came out, and I got a 33! I’m really happy with that, since that’s the average score at Northwestern (my top school, applying ED). Since that composite was without writing, however, I also had to send in my 31 with writing. I’ve already sent those two in to all of my schools, but THAT BEING SAID, should I also send in my SAT scores? My highest composite is a 2180, which is also within Northwestern’s average–but on a 1600 scale, I have a 1390, which is pretty low (since 1600 is just CR and math, and SAT math is not my strong suit.) So, should I send that score in as well, or just stick with the ACT? Also, I’m a National Merit semi-finalist, so I’m not sure if that means I should definitely send in my SAT to show colleges that my PSAT score wasn’t a weird fluke.
Any input would be appreciated!!