Honestly, ang pinaka-reliable way to know talaga is with a pregnancy test or blood test from your doctor, kasi implantation bleeding at actual period can look so similar na mahirap i-distinguish lang based sa appearance alone, ang color and cramping you're describing could go either way. A few of my mum friends thought they had their period pero turned out they were pregnant, so it's really better to get checked para sure, especially since you had a delay na. Good luck, mama, and let me know what the doctor says!