Is true that the longer you have your tubes tied you can get prenany?

No. Unless your tubal sterilization failed (roughly 1 in 100) your sterilization is permanent.
Still Possible. There is a slight risk of becoming pregnant after tubal ligation. This happens to about 5 out of 1, 000 women after 1 year. After a total of 5 years following tubal ligation, about 13 out of 1, 000 women will have become pregnant.