Having an only child have their advantages and disadvantages but many of us can not have more than one child. I, for one, can not have any more children.
I had a wonderful pregnancy, no morning sickness except for the usual aches and pains when the baby grew as the months went on. Labor was good, had an epidural which it went great until after almost two hours of pushing, my dd's head was pressing on my scatic nerve and causing pain down on my leg. No matter what and how the nurses did, cranked up the epidural but it did not take care of the pain until my OB doc came in and feel around. UH OH! My dd's head was compressing on the side of my pelvis rather than going into the birth canal. So it called for emergency c-section. From then on, it went downhill, had a problematic recovery, a hot and cold chills that I could not bounce back, in so much pain in belly and back, and then later within a month, I had infection of the c-section and mastitis on top of it. It was hell for me! From that day on, with so many visits to doctors, they still can not find out why I am still in pain and the closest thing to it, would be fibromyglia and not yet dx for it. Aches and pain on top of it every day. Another thing was my age, I just turned 39 years old when I had my dd six years ago.
I didnt want to endure all of this again, risking myself more pain and possibly crippling me any further and having a down's syndrome baby risks, I decided to have my tubes tied. I would love to have more but I have MORE love to give to my daughter and be able to focus on her and making her be whatever she wants to be when she grows up. She would not have to fight for room, toys, etc. but still have some social problems of sharing and problem solving without yelling to share with her classmates without bullying. If she had another sibling, she probably woudl have some idea to share or not share at all. Due to the ecomonic downfall, with me lost my job just before I found out I was pregnant, and hubby having a full time job that ended badly, as much as I hated it, we had to go on Public Aid for the very first time in our lives when we have worked since high school. Limited funds but glad to cash in my 401K to pay for my dd's crib, clothes, diapers, etc. while I had to declare bankruptcy on my house, my truck and everything I had lost before we were married, put down a downpayment on a new house (under hubby'sname), got a used van and we made it so far.
As for being jealous, I am happy with what I got and the decision we both made in not having any more kids to burden ourselves broke or depending on the Public Aid (some folks would just churn out more kids, for more money, more food stamps and stay on welfare).
There are questions you might need to ask yourself: is it for selfish reasons because of the attention the pregnant moms are getting? If not, you may just want to have more of your husband's children because you love him and want more of his "clones" LOL...that is not a selfish reason.
As for the risks, would you risk it again? Even it might jeopardize yourself and the fetus? are you willing to face the ramifications of having permanent damage to yourself and the fetus? Are you willing to take on a handicap child if something went wrong? Or the co pays of expensive hospital stays?
Would you be able to afford the extra expense of adding on another room? If so, how much would it set you back? Can you do both in supporting the extra $ for adding a bedroom or bigger mortgage AND Zach's college education?
Honestly, I think it is a normal feeling but do keep talking to your husband in how you feel and how he feels about having a new baby in the family. Do not worry about the age gap because I have two nephews that was that age when their baby sister came along and they were doting on her and now they hated her LOLOL and they fight like cats and dogs LOLOL.
Once you have made your decision, you wont regret it, ever!
Good luck!