Should I have another?

My husband and I have been together 3 years both married before he had no kids I had 2 ages 12 and 14 ! Last year after 18 months together we had discussed having a little for most of our relationship we decided we would try - we were 36 at the time ! We were told we may not have a easy time as he had low testosterone and it could take a long time but we were blessed and it took 2 months to get pregnant ! We had a healthy little 3 months ago and we want another but we are now 37 - the Doctor’s say the risk are no higher than with her and they don’t see a issue with trying ! I really don’t want this little to grow up without a full sibling - I want her to have someone to ! Am i selfish to want another and would you be stressed about having another at 37-38 ? I am a stay at home Mom so she gets plenty of love and attention ! Her older siblings love her - please no negative comments and older Moms like me with two littles how hard was it