39 and pregnant and scared

Hi all. I just found out I am pregnant 4 days ago. I had a bit of bleeding that I thought was period starting but it didn’t even fill half a tampon then stopped. So a few days later I took a test because I suspected it was implantation bleeding and yep- pregnant. I have 2 teenage daughters from first marriage and a 3 year old between me and my husband. We were pregnant again 2 years ago and we had to medically terminate that pregnancy at 22 weeks because our baby had lethal skeletal dysplasia and wouldn’t survive outside the womb. Doctors said that it is usually (like 98% of the time) a fluke genetic mutation but we never had any testing done to make sure it didn’t come from our genes. So I said I’m never have another after that. It was so traumatic. My husband never got fixed and I can’t take birth control so we always just cycle tracked and tried to be careful. But here we are. I’m so scared this baby won’t be healthy either. I’m scared that I’m too old to do this. I’m scared. Prayers and success stories appreciated. Of course we will love this rainbow baby so much but right now I’m so overwhelmed and scared. First doc appt is Monday.