3 mature follicles?

So I went for a mid-cycle scan and on my right ovary there is two follicles that are mature 20mm and 21mm.... Then on my left ovary there is a follicle that is 17mm... My doctor said she dont consider a follicle 17mm to be mature.. I didnt ask but maybe you know. How big does a follicle have to be to ovulate?? I on cycle day 13.....I took Soy Isoflavones 200mg this cycle.... This is the first mid-cycle scan I have had. Thanks

[Heather5]

Three going follicles are great! Usually anything over 18 mm is considered mature. Whether the 17 mm one will ovulate or not, probably depends on when you start the ovulation process (or if you'll be using a trigger shot), but I would say the chances are pretty good that the 17 mm one could be ready, too! Best of luck this month!