Eh, 12 hari delay memang bikin panik kan, tapi negative UPT twice is a good sign you're not pregnant lah, sometimes our body just does weird things, especially if stress, diet changes, or exercise routine berubah recently. The feeling macam nak period tapi takda actual bleeding boleh jadi hormonal fluctuation je or even your body preparing but not quite there yet, tapi honestly sebaiknya gi jumpa doctor untuk check, bukan panik pun, just to confirm everything okay lah, maybe hormonal imbalance or something simple yang boleh sort out easily. Aku punya few mum friends pernah experience gini, and bila check out it was just stress or thyroid stuff, so don't worry la, just get it confirmed to be safe!