I pay a little visit to my cervix every single evening in the shower. That's how I know when my fertility is returning.
After baby # 3 (the 1st one I new how to chart after), I had 3 periods before ovulating. After baby #4, I had 2 before O'ing. So I was super surprised to discover very obvious ovulation signs before seeing my 1st PPAF this time! My cervix opened over the course of a few days, EWCM increased until it was, well, a ton, and everything down there was swollen & soft. We didn't dtd during those few days because I'm not quite ready yet (all of this was just a few weeks ago, my baby is 11mos). Eight days after O'ing, I had my 1st PPAF. I was all excited at my ability to know exactly what my body was doing!
You can still be fertile before seeing a period. There are plenty of posts here on mdc from pregnant mamas that don't know how far along they are because they never had a period! Statistically speaking, they say a women is more likely to ovulate after
seeing her periods return if she has her 1st PPAF before her baby is about 12 mos old. And, she's more likely to ovulate before
her 1st period if she's reached 12mos PP or so. That's just statistics, & can't be relied upon obviously, but I find it interesting. It just happened to be true for me!
Anyway, go say hi to your cervix! It will tell you what's going on fertility-wise if you're paying close attention. Usually anyway.