I'm glad your boys are doing well - and I'm so sorry they didn't find a membrane.
I would really, really encourage you to get that referral, and see an actual maternal-fetal specialist. The problem with momo twins is that they're really rare, and doctors who don't know much about them aren't going to give you proper treatment. They'll be tempted to treat them like di-mo's, which are more common. The statistics really show that inpatient monitoring after viability (usually somewhere from 24-28 weeks) significantly increases the odds of a live birth for momos.
I know this is scary, and I remember the strange feeling of voluntarily signing up for a hospital stay that I really didn't want to have. You're choosing to do something really hard, but it honestly is the only way to up the odds of your boys getting here safety. It's not a guarantee, but this is a very rare condition, and there's no cure but birth, and only monitoring is going to tell you when that birth needs to happen. It is NOT a normal twin pregnancy (as far as there is such a thing).
It used to be that momo twins had a survival rate of just 50%. Now, with the intensive monitoring, it's over 90%. That's a huge difference and, in my opinion, it makes the hospital stay and early delivery totally worth it. And I'm saying that as someone who did both, and hated doing both. It sucked. But it was so worth it, because my two little girls are here safely. I will never forget how their cords looked when they were born: twisted together over and over and tied in a true knot. And it's not even like when a singleton has a true knot: in this case, each end was attached to a squirmy baby, who could pull it tight at any time, just by rolling away from her sister.
So . . . yeah. Having been there, I encourage you to fight for proper care. Your boys deserve to be treated according to the proper standard of care for momos, and that's not outpatient - - not after viability, anyways.