Menstrual Cycle related. Of the delay?

My periods were never got delayed more than 3 to 5 days. I am trying for my 2nd pregnancy and don't have any health issues or any condition in that matter. My first delivery was a C section at 2021. My last period came on Dec 4th 2024. But i am sexually very active. I dont have any pregnancy symptoms or period symptoms. But, My periods delayed for 2 weeks and just today morning i saw a blood discharge. I have taken home pregnancy test 3 days before it was negative and also took blood test 2days before that was also negative. So, Currently i am confused as to why this delay happened? Or could this be implantation bleeding? or this is my next cycle? Is there any chance that i have any underlying medical issue that is the reason of the delay?