Pregnancy after vasectomy?

Hello all, I am curious if there is anyone in this community who has personally gotten pregnant from their SO after he had a vasectomy? My husband had one late last year and was told he should be clear after 12 ejaculations.. well that put us sometime into December. I've been kind of holding onto the hope that I could still get pregnant, like if the procedure wasn't done properly or something. He had never gone back for his follow up so we aren't positive, but it's been months and no pregnancy. The reason I'm so hopeful is that I've always wanted another child but he just isn't on the same page. I didn't feel comfortable telling him what to do with his own body but I hoped he wouldn't go through with it knowing my feelings. I was wrong and I've been in turmoil ever since. Anyway, I've urged him to go back to the doctor and get checked so I can try and put it all behind me instead of clinging to the hope he isn't 100% clear because it is literally killing me and no one I know can relate. It's been 9 months now. So I'm wondering if anyone has had experience with this? What advice might you have? Thanks!