Im 30 weeks and 5 days preg. i have had 2 other pregnancies and one was 4 years ago and they had to terminate ?

because of a abnormality that the baby would not survive. when i was 18 which was 7 years ago i had an abortion. would u get ur tubes tied? this will be my first baby and i wanna get my tubes tied but 3 drs. told me that they will not do it cuz im only 25 and could have more babies but my cervix is very incompetant. i only have 1.38 cm left in length of my cervix...what would u do?