Hello Thanks for your query. Here are the statistics you asked for : 35-50% of patients who conceive after a tubal ligation are reported to experience an ectopic pregnancy. Failure after bipolar tubal cautery is more likely to result in ectopic pregnancy than is occlusion using suture, rings, or clips. This failure is attributed to fistula formation that allows sperm passage. In one study, 33% of pregnancies occurring after tubal ligation were ectopic; those who underwent electrocautery and women younger than 35 years were at higher risk. One word of positivity though for you : Ectopic pregnancies following tubal sterilizations usually occur 2 or more years after sterilization rather than immediately after. In the first year, only about 6% of sterilization failures result in ectopic pregnancy. As your B HCG values are doubling, please do not worry till you have your scan. take care.