I have had my tubes tied for 2 and a half years but i'm 2 months late on my period now ace pg test was negative what could this be from?

Some thoughts...: In a woman with regular periods, some causes of a late period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, some types of medicines, hormonal imbalances, etc… Seeing an Ob-Gyn doctor is a good idea if symptoms are persistent, recurring, or worrisome. Pregnancy is very, very rare if tubes are tied.