Can sudden and strong scare cause problem at 23 week of pregnancy?i am high risk pregnant, with history of pprom, currently low cervix w/cerclage

You should be ok: Preterm Labor and/or weak cervix are very complex conditions. You already do have the best evidence based preventative tool in use: a cerclage. PERSISTENT high emotional stress is not good for your overall health, but a one time high stress event should not adversely affect your pregnancy. If you have leakage of fluid or persistant vaginal bloody discharge, seek MD eval. Otherwise you should be ok