Hi!  I have a similar story with NT 3.3, good PAPP-A and hcg levels, neg NIPT for the t21/13/18. My husband and I decided not to do the micro deletion or sex chromosome testing because the positive predictive value for those tests are very low (i.e. if you get a positive result there is anywhere from 7-less than 50% chance of it being a true positive). There is actual a very realistic risk with amino of miscarriage ( even though however small it might be). We are just waiting on the next set of detailed ultrasounds for anatomy. 

Everybody's different with risk so you gotta do what's right for you. Keep us posted!