Yup! In some cases processing time is too quick because of the local office processing timelines and for @TF257384 as I can see local field office is (Philadelphia) their average processing times are four months I guess !
Check this link https://www.visajourney.com/timeline/aoslist.php?vtype=1&op8=Philadelphia+PA&interview=&xfr=&op1=2&op2=d&op3=&op4=1&op5=5%2C6%2C8%2C9%2C10%2C11&cfl=0
As I can check for my local field office its more than six months...