No period for 3 mos and my tubes been tied for 5 years can i be preagant?

Rarely, but yes: While chance of pregnancy is remote at 1%, you should simply exclude with pregnancy test. If negative, then see doctor to evaluate female hormones & ovultory function.

Unlikely not imposs: Sterilization is the most effective form of birth control, but it is not 100% perfect. There are failures and you should get a pregnancy test as soon as possible. There is also an increased risk of ectopic or tubal pregnancy with any type of tubal surgery, tho unlikely at 3 mos ...