Ah sis, okay lang yan! Posterior placenta lang yan meaning ang placenta mo ay nasa back wall ng uterus, which is actually normal at common pa. Ang Grade 2 naman ay about the maturity ng placenta mo, so that's normal din for your stage of pregnancy. What's important dito is yung 1.35cm distance from the cervical opening, from what a few of us mums talked about sa OB appointments, as long as it's far enough from the cervix (your doctor will say kung okay na yan or kailangan i-monitor), usually okay na siya. But honestly, you should ask your OB about this finding specifically kasi sila ang makakasiguro kung may kailangan i-monitor or kung completely normal lang sya based sa how far along you are. Wag mag-alala too much muna, and just follow up with your doctor okay?