Yep, #1 rule for LAM is no period. (Hence the "amennorhea" part.) When I first started getting in to teaching FAM, I spent a good deal of time studying cycles of women who were breastfeeding. I have to say it's really interesting how each woman's body is so individual in how it responds to it all. For some women, the "rules" don't work... my thoughts are sometimes it's a metabolic difference, etc. I also made observations personally that more skin to skin time with my baby while nursing kept fertile CM away. I think as with anything we have to remember it's not one size fits all, you have to constantly, almost daily, reevaluate the state of your fertility. I suppose it's not much different from FAM/NFP in that respect, except that it gets very tedious at times when you have a load of fertile CM and then no ovulation.
One of my first cycles back with my first son, when he was 9 or 10 months... I had every sign of ovulation. Several days of EWCM, cervix was open and soft, ovulation pain, even two positive OPK tests. And then no temp shift. I've also seen this on a chart of a woman who was going through a very stressful time (her mother had just passed away) and I'm certain it happens to women who have PCOS.
I O'ed on CD15 this cycle. Didn't a few others have "early" ovulation this month too? I wonder if it had to do with the solstice. We are in the process of nightweaning out 18 month old, so I'm confident that things are going to get more and more regular here. It would be nice if every cycle were this easy.