Shorter cycle with trigger shot

Has anyone had issues once adding trigger shot having shorter cycles? I had never had anything shorter than 24 days ever before starting medication and while I was only on letrozole I had 26 day cycles like clockwork with a 15day luteal phase. My second month with a trigger shot I started spotting 7dpiui with full on period by 11dpiui (22 day cycle) and now this month I'm pretty sure my period full on started at 7dpiui making my cycle 18 days long?!? What is going on here???