I think a lot of older parents are having children. Technology and better health care has made it possible. They will put you in the "high risk" category, because you are over age 35. I would highly recommend an amniocentesis. I had one to rule out downs and other abnormalities. It was not as bad as it sounds, it didn't hurt at all, just make sure you rest afterward. I would only recommend doing it if you plan on doing something to terminate the pregnancy if it comes back positive OR you would like to be better prepared for afterward if it comes back positive, otherwise what is the point of knowing and risking miscarriage to have the test. It is a good idea to have it, just to be aware. Let us know what you find out. I was worried that I would be the oldest mom when my son was in kindergarten, but I really think there is a trend toward staring second families, or just having babies later in life. Fertility drugs and changes in the women's work roles are making it more and more common. I am really enjoying my son, I feel like I really know what I'm going this time because I've already done it before, and I'm more mature. I was only 20 and 22 when I had the girls. At first, my girls were jealous, even as teens, but they got over it quickly. We are trying for another so my son can grow up with a sibling close in age, but so far (8 months later) I'm not pregnant yet. It will happen if it's supposed to. I won't take it as far as fertility drugs and what not. I'm fine either way. PS The older you are, the more likely it is to have multiples (twins, triplets, etc.)
You can sign up for weekly emails from babycenter.com that will let you know how the baby is growing, it's really fun to think about whether it's growing fingernails or hair that particular week.
Take your prenatal vitamins every day and consider taking Expecta as well, it's a DHA supplement. I took it with my son and it helps with brain and eye development. He says over 200 words and he's only 18-months-old. I also went to school to become a medical transcriptionist so I could stay home with him, best decision I've made because now I can be with him all the time and work around his sleep schedule. If anyone is interested in how the school I went to (it's 100% online) let me know....Congratulations!