I've been feeding my son for 15 months now, exclusively. My period eventually came back in January (so when he was just over a year old).
The first two were like clockwork, but over the past 4 or so weeks he's been unwell/teething & therefore feeding a little more than usual. I'm still waiting for my 3rd period 
Has anyone else experienced this?? I've no idea if it's normal as never BF this long with others.
Did pregnancy test a few days ago btw & all negative! Any ideas??