Egg not reptured last month. Raptured?

Hi, I am planning to have a second child. I am a mother of a daughter. She is 4.5 yr old. I am trying to concieve since last 4 month and consulting a aayurvedic doctor. He suggested for ovulation study. Both the ovaries showing 1-1 egg. One was 18mm on 14th day and second was 11 mm and endo is 11mm. This situation is same till the 19th day. But egg was not reptured. My doctor told.me that everything will be ok. There is no issue in your report. I want to ask below mentioned questions 1. If egg has not reptured last month, it is possible to repture in next month cycle ? 2. What are the reasons for not repturing the egg? 3. Doctor told me that if my endo will be 10mm than egg will be raptured? Kindly give your suggestions.