Uy, sis, kahit laging negative ang PT mo, kailangan mo talaga ng check-up sa doctor, pwedeng may iba pang reasons bakit nawawala ang period mo besides pregnancy, at ang pills mo rin ay pwedeng mag-affect. Hindi ito normal na palampasin ng dalawang buwan, so please don't wait pa, book an appointment or go to a clinic kaagad, okay? Your OB can check what's really going on at di ka na mag-alala. Sending you hugs, alam ko stressful ito!