Anak, seryoso na, please go see your OB or go to the clinic/hospital agad, hindi lang bukas ha. The pain, the nausea, at ang delayed period kahit negative ang PT, those things need proper checking talaga, kasi maraming reasons kung bakit nangyari yan.
I know it's scary, pero alam mo, one of my mum friends had similar symptoms tapos hindi pregnancy pala pero kailangan niya ng treatment. Better safe than sorry, lalo na may sakit ka na. Call your doctor or go to the ER kung pakiramdam mo talaga malala okay? Sending you strength, mama.