Ay sis, I totally understand your worry kasi ganyan din ang nangyari sa isang mum friend ko, delayed period, negative PT pero parang may symptoms, at ang antok na sobra sobra talaga. Honestly, given na matagal na nang delayed ang period mo, I'd really suggest going back to your OB para magpa-blood test instead of PT lang, kasi sometimes hindi pa visible sa urine at makikita na agad sa blood, plus they can rule out other things na pwedeng mag-cause ng delay at fatigue like hormonal imbalance or thyroid issues. Don't worry, you're doing the right thing by checking, maraming possible reasons ito, hindi lang pregnancy, pero your doc can sort it out properly para sure na alam nyo ano ang nangyayari.