baby fever

I feel so guilty, my s/o has baby fever, all of his siblings have 3-4 kids. And his mom recently told me shes ready for new grandbabies. we're getting older and it never happened for us. I'm 26 hes 29. my periods are irregular, I have slightly elevated testosterone, and I try to be nonchalant about the baby talk, even though deep down inside I've BEEN ready. what are some ways I can tell my him and his family about my situation?