Feeling pressured by Dr to get Tubal Ligation PLEASE HELP

Hello Ladies, so I'm 28 yrs old and I'm currently a high risk pregnancy due go type 2 diabetes and history of pre term labor. This is my 2nd pregnancy, and I feel like its been going good up u til this point ... At 29 weeks 2 d I was diagnosed with polyhydramnios which Dr states is borderline high n that I shouldn't lose sleep over it ( this is coming from my high risk obgyn specialist ) so my primary OB is telling me that because I'm high risk and I'm already 28 that if i get pregnant again I would be risking it because as I get older the more complications I would get due to my diabetes. I am currently on insulin and checking my blood sugars 7 times a day and I am supposed to jeep them below 90 fasting and under 120 2 hours after I eat. And considering my blood work and all my blood sugar checks I have been compliant and have been working out and have felt better than ever. Both doctors state that my sugars are under control and are really happy with my numbers which is why I don't understand why he keeps trying to push this tubal on me. So far baby is growing right on point and is looking healthy and besides the little extra fluid no other problems have occurred. Dr is being really persistent on this tubal though what should I do ? I'm due march 28th.