In your situation, I had the baby. She is 10 months old now and is the light of my life. She wasn’t planned, and I cried out of shock and fear when I found out I was pregnant. Like you, I was married, owned a house, had (have) a good career. I knew I wanted children, I thought I had a couple more selfish years left. I felt overwhelmed and fearful, but it never crossed my mind not to go through with the pregnancy, and I don’t have any fertility difficulties.
There’s nothing wrong with not wanting children. It’s okay to say that there are other things that are more important to you. I think the fact that you are even considering a termination when in a stable relationship, owning your own home, and having a career, especially given you know you will struggle to conceive later, means you probably don’t really want to have a child. If that’s the case, you need to tell your DH and let him decide what he wants, too.
If you do want to have a child, then this could well be your baby. Sometimes the best things aren’t planned. If you are going to be a mother, you’ll need to get used to not being in control - this is a good introduction to motherhood! But if you do choose to have the baby, allow yourself to grieve the loss of the life you had envisioned, and then let go. Growing up feeling resented and like an unwanted burden would be so damaging to a child. If you decide to go through with the pregnancy, do so with your whole heart.
Wishing you the best, whatever you decide in the end.