Confused as hell!😣

Hi moms. I'm so annoyed right now! My period is 5 days late and every pregnancy test I take is negative, not sure if anyone has had this experience and turned out to be pregnant or maybe there was another explanation? I'm wondering if it's not the breastfeeding that's delayed my period again, it's been regular for the past 3 months up until now.

Any similar experiences or current dilemmas??