Hey Everyone , Happy 2023 🎆

I need your advice, so for the past 3 months my period has been coming in between the dates 24th-28th and never came out of that time. As per my last cycle (November) and glow’s predictions for my December cycle it should have already come the 26th. See screenshot below. Nonetheless it still hasn’t come as yet. On Dec 30th (Friday) I ran a HCG test and it came out negative. (At this time I was around 4 days late as glowed showed.) Yet still no sign of my period.

Can anyone help and shed a little light on what might be happening? I would really appreciate it! Is there a reason to worry?