Breastfeeding/periods

I’m currently breastfeeding my 9 month old, I started my period when she was 7 months old this was from April 30-May 4th.. haven’t gotten it since, was wondering if it was normal to have an irregular period while breastfeeding or should it be on time like it usually has in the past (before I got pregnant with my now second child I was always an on time person)? I did take a test that came out negative and that was over a week ago. The tracker says I’m 16 days late, has anyone gone through the same thing or am I freaking for nothing 😅