Implantation after 20 days of ovulation. no period. what does this mean?

May not ovulate: Implantation generally occurs around 6 1/2 to 7 days post ovulation. Unless you ovulated late in your cycle and are pregnant, the most common reason for not getting a period is that you might have had anovulatory cycle where you did not release an egg. This can happen from time to time and you should not worry. If these kind of cycles continue you may would to consult with your gyn. Good luck.