How can you tell if the flange you are using to pump is the correct size. I tried for the first time last night when my breast was very full before lying down. The nipple appeared to have plenty of room in the flange. I had great success with milk flow but when I was done the area around my nipple, the areaola, was swollen. Does the opening in the flange need to encase the areaola too or just the nipple? My breast felt bruised through the next day. I can't tell if the size was wrong or the speed or maybe both.