I'm 34 yrs old and want to have a baby?

I am divorced 10 years ago and had 2 kids from that marriage. My girl is 13 and my son is 12. I am remarried and have been with my new husband for 8 1/2 years already. I have been on the IUD but I will be removing it next week. My husband asked if I want to have a baby since he had 2 boys from his previous relationship. He hardly see his kids since his ex is in a difficult relationship where her new boyfriend don't let the kids come over or even see their dad. My husband treats my kids like if they were his own and my kids see their real dad all the time but I have noticed that my husband wants a baby of our own since we don't have one. When I was 27 I wanted a baby and he said no because we didn't have our own house. We bough our house 3 years ago with 4 bedrooms and one of them we made it into an office. He was looking at the office this past weekend and said that room should be a nursery but now I'm the one that don't feel ready to have a baby since I'm already 34 and I think is some what dangerous to become parents at this age. Well my husband is only 30 I'm 4 years older than him but it seems like he is ready now more then when I was 25 and I wanted a baby and he didn't. There are a lot of things that come to my head when he brings up the subject. It's been so long since I've deal with a baby that I'm kind of scare. Is the baby gonna grow with an old mom? would my 13 and 12 year old be embarred to be teenagers and have a pregnant mom? I have been told i don't look my age since I'm petite but I know I will be 35 when I have this baby and my kids will be teen agers. Am I going to put this baby's health at risk since I'm not in my 20's anymore? I'm so confused but the more I think about it time is running and I'm not getting any younger so please I need help and a good advice. BTW I am married to a wonderful man that I love with all my heart and he feels the same but I'm afraid that he would treat my kids any different after having his own.