Short period cycle

Mary • First baby born May 2020 Baby #2 due April 2022

I came off BC pills the end of February. The first few cycles were 24 days. My last cycle went down to 23 days and this cycle I started spotting at 22 days. Does anybody else have experience with shorter cycles? I just had my yearly exam at the gyno last week and she said the period isn’t considered irregular until under 21 days. Any advice?