What on earth??

Normally, glow/<a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> are SPOT on with my periods. My period is now 3 days late, HPT was negative x2. I’m super bloated feel like I need to poop but can’t. Super exhausted (normal though) & just feel off. If I’m obviously not pregnant because of the negative HPT what could be wrong?? I feel like I can just sneeze & AF with arrive. But nothing!! Ugh! Advice please?!