Hai sayang, I understand lah the waiting game is super stressful! Tapi honestly, kalau UPT still negative after 3 weeks late, sebaiknya you go see your doctor to check what's going on, bisa jadi ada hormonal issue atau something else yang perlu proper check, bukan tips je yang boleh tolong here. A few of my mum friends pun pernah experience delayed period for different reasons, so don't worry, doctor can advise you properly on what to do next. Hang in there!