My period didn’t return until after 15 mos. DC was EBF until transitioning to solids, and STTN at 8 weeks. (No, we didn’t do any special training. I nursed to sleep until close to a year.)
Four years later, we decided to try for a second. Pulled the goalie and caught pregnant the first month. (FTR, this one woke every 2 hours for the first year.)