20mm is a good size follicle hun should mean you ovulate soon. It's the small ones that cause all the trouble as they prevent the eggs from releasing from the ovaries. They may do ovarian drilling straight away which is basically a hot stick that burns lots of holes in your ovaries allowing the eggs somewhere to release from, if you search it on you tube you can actually see how it is done. Or they may try you on clomid first like me, the side effects aren't great but if it works ......