Late period while breastfeeding

Kasey

Hi all! 8 month PP. I am exclusively breastfeeding. I got my first period back at 7 month PP. I had a positive ovulation test on June 11. And then cramping a week or week and a half ago which I for sure thought my period was coming. Well now I’m 40 days since last period and over the weekend I took a pregnancy test and it was negative. Am I just late because of breastfeeding or did anyone else have this problem?