Hay, mahirap sabihin based on timing lang sis kasi implantation bleeding usually happens bago pa man ang missed period mo, so kung 2 days delay ka na baka mas likely na period mo na or hormonal shift lang. Magtest ka na ng pregnancy test para sure, lalo na kung gusto mo ng peace of mind, better to know now than mag-worry pa, and honestly a few of us dito sa circle ko agad nag-test pagka-delay kahit konti lang kasi di kami matulog ng mahimbing haha! Let me know what happens, pero if you're still unsure or may weird symptoms ka, sabi rin ni friend ko na OB niya to just check in with doctor para ma-advise properly, okay?