Hubby says "Not Yet" for fostering/adoption

Annie • 23 years old. Diagnosed with PCOS & hypothyroidism. Married for 5 years. Ellie Rose 💕👶🏼 & Millie Jean 💕🤰🏼
Hey ladies. 🙋🏼 I need some advice. A little back story on my husband and I... 
We got married young. I was 18, he was 23. We grew up together and he's my absolute best friend. Two year of marriage later and we decided to try to start our family. He was hesitant at first but after us praying about it for almost a year we decided it was time.💃🏼
We got busy but nothing happened. That's when we discovered that I have PCOS and hypothyroidism, a thyroid disease. Both play big roles in conceiving. My OBGYN decided it was time for a laparoscopic surgery to make sure there were no abnormalities. We were in the clear, minus a little inflammation. But still...no pregnancy. 
It's now been 10 months since TTC and I've basically given up. 4 rounds of Clomid and I only ovulated twice for sure. My thyroid and PCOS are still a problem. It's just not gonna work - physically - under these conditions, you know? 😔 
That's when we started talking about fostering and adoption. We've talked about this many times, even when we were dating. He has said that even if we do have kids he wants to foster and/or adopt because he sees a need in our community and feels it's our responsibility as Christians to step up for these orphans. I couldn't agree more! Slowly over the past two years of our marriage I have gotten a stronger fire for adoption and fostering. Sometimes I even think I would rather adopt than have my own kids!! 
The only problem is that now my hubby doesn't think it's the right time to foster or adopt. Maybe in a year, two years, he doesn't really know. He figures he'll know when it's the right time. 
What does that mean?? How can I help him move this process along?? Haha. I want to start a family and help the mommy-less babies in foster care!