Hay, alam ko yan ang worry mo! Honestly, three months delayed is worth checking with your OB talaga, kasi pwedeng maraming reasons yan: stress, hormonal changes especially kung recently ka pang nag-recover from giving birth, or kahit medication; pero some of my mum friends din nakaranas ng false negatives early on, so better safe than sorry with a blood test sa doctor para sure. Kaka-postpartum ka pa lang in May kaya possible pa rin na irregular ang cycle mo ngayon, pero don't wait pa if it's been three months na, go see your OB para ma-check properly at ma-rule out anything else that might need attention, okay?