Centering?

My dr pretty much forced me into something called centering. I didn’t know what it was about so I took my husband. It was me and several other girls that were about as far along as me, and we pretty much had our appointment together. We weighed together, blood pressure, checked babies heart beat, all in a big room. And it turns out I have high blood pressure, but I don’t know if it was because I was so stressed by the group situation. It was super awkward for me. Then we sat in a circle and did charades to act out pregnancy symptoms. One was vaginal discharge, how and why would you act that out? My husband got up and left almost immediately but I stuck it out. For two hours. I told the nurse I was never coming back. Why would anyone want to do that?