Please help me!

Fl

I’ve had my hormonal iud removed at January 4th, and the gynaecologist saw that I just had an ovulation at that point. Since then, I’ve been having regular cycles of 27 days. I was supposed to get my period last Thursday (Monday today), but I haven’t gotten my period yet and multiple pregnancy tests are negative. I might have a late ovulation (check the bbt)? What could be the issue here?