3 weeks late for my period tubes was tied 9 months ago, sharp pains on right lower side mild cramping more discharge could i be pregnant?

Pregnancy test!!!: No form of birth control, even tubal sterilization, is 100% efficacious. Tubal sterilizations can still fail at a lower rate than other forms of birth control. Please do a pregnancy test and make sure you are not pregnant. If you are pregnant that pain of the right lower side may be an ectopic pregnancy which is a medical emergency that is an increased risk in failed tubal sterilizations.

See A Provider ASAP!: You need to see a provider and get an ultrasound and pregnancy test asap. Although pregnancies are rare after a btl, they do occur. Your symptoms are worrisome. Please see an ob/gyn provider soon!