Join the no af club! DD is 16 months and no AF for me; I would be in tears if I gave it much thought, because I want to ttc in a couple months and it doesn't seem likely. You surely are normal. The only reason you might have to be concerned is if you are far below a normal healthy weight. The average return of AF if doing ecological bf is 14.5 months, but can be far later. And it's all normal. Aren't our bodies wonderfully diverse?
with DD, got it back @ 11 months with DS 23.5 MONTHS! I wasn't ready to TTC at that point, so I was happy to have AF on extended vacation. After about 6 months, we tried to concieve, and succeded our first month. Maybe your babe or body is trying to tell you it is not time yet?