Welcome to the forum! My second daughter was born five days after I turned 40. She was conceived through IVF due to life-long infertility (not my age). There certainly are challenges in conceiving at 40 which are less evident in the 20s and 30s. You might like to read this article on the topic: Older Mothers: the good, the bad and the ugly! (npt a very flattering title!)
I remember going for my booking visit at the hospital for my second baby and commenting to the midwife that at 39 I must be one of their oldest mothers. The nurse laughed at me and told me to have a better look at the women in the waiting room. On the way out I did and realised that the vast majority of women there were not much younger than me, many were my age and some looked older!
One very important point that I can't make strongly enough to you is the value of preconception care. You might like to read this article: Planning for Pregnancy: Preconception Care
Again welcome to the forum!