I have a question about ectopic pregnancies after a tubal ligation. higher risk than before?

Rare: It is rare to get pregnant after tubal ligation, if fertilization occurs by chance it is possible to have tubal pregnancy, then high chances the embryo getting lodged in the tube.

Yes: It is a relative risk. Risk of pregnancy is tremendously decreased for obvious reason. But if it happens the risk of ectopic is higher. If a period is missed immediately do a pregnancy test. If positive called your ob/gyn asap.