possible buntis po ba??

mga mumshie pahelp nmn po..ung gf ko last august mens nya 18 then sept 25 then oct 25 then nov 26 then dec 30 but it last for about 3 to 4 days lng tapos last week bakit po may signs na darating ung dalaw nya like cramping sa balakang. bloated ung lower abdomen nya or pus on..tapos may breast tenderness din tsaka moody always.bakit ganun na ang aga nmn dumating ng signs na darating dalaw nya..is it possible po ba na buntis xia