Breast feeding/Missed Period

I’m currently NOT ttc… I have a 7 month old that is completely breastfed, I got my cycle back in September and it’s been regular up to now.. I typically come on the last or first day of the month, but I haven’t gotten my period. Is it normal to completely miss a period while breastfeeding even if your cycle was returned? Or could this be the cycle changing? I’ve never had an irregular period even when my 3 year old was a baby and breastfed it was never like this..