I personally think ONE child is the ABSOLUTE HARDEST number EVER!!!
For so many reasons I think having a single child is a disservice. BUT I don't think having an unwanted child is a good way to go either. How will you give that child what s/he deserves if your resent him/her, don't want him/her. That is NOT a nice or responsible thing to do to a child.
You want to be a career woman rather than a mother...that's who you want to be. So...be that.
Sit with yourself ALONE--You know, I have a friend who made reservations and Marriot just for herself to have a night alone (actually it was a whole weekend) with none of her children or hubby near by--think about your life, your priorities, what's important to you, what brings you joy, what makes you feel like you have purpose. Feel who you are.
Base your choice on those things...not based soley on what your hubby wants. The fact of the matter is that when your hubby pictures another baby he's seeing a complete portrait of family and you in your role as mother. If you cannot feel peace in your choice to have another child, this will only breed resentment, disappointment, frustration, disrespect, and an overall sense of failure and disillusionment. This is not what you're looking for in pleasing your man.
I think you'll find another child to be a blessing and wonder how you lived a moment without him/her; however, I believe this will happen ONLY IF you come to it from an inner desire, rather than a place of submitting to the will of someone else.
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One of my step-sons is an "only" and EVERYONE can tell. He can NOT share ANYTHING. He needs to have 100 percent of everything, get angry when others get what he wants, cannot understand why other people can have something when he can't but doesn't want others to have something he has, he values gifts more than interaction because his Mama raises him that way--things rather than her time and interactions. Soo, if you choose to stick with one, get him involved with others and charities to have compassion and learn to work with others and understand status.
My son's best friend is an only child, one of the best kids on the planet. His Mom is constantly asking to "borrow" my son for trips, camping, when she wants to go out so that her son isn't alone and is occupied. So, she borrows siblings for him.
I was raised as an only child; being the only one my mother gave live birth to, but my father's sixth child. I remember always wanting to be with my sibling. I remember always being left alone when my mom had to work or went out. I remember "making" friends my sisters and brothers. Now as I'm older, having just recently witness my mother with her siblings deal with the passing of their mother, I realized I have ALL that work, suffering, planning, paying, and healing to do BY MYSELF. There is NO ONE to share the memories with, no one to share the burden with.
My mom, just like my stepson's mom, places a lot of responsibility on me to help her, make her happy and proud, to be her bestfriend, etc...because she no longer has a husband nor does she have any other children to find belonging with--she's quite lonely and it all rests upon me and my family to make up the difference. I love her, but it is a burden at times, we have to skirt our plans for holidays and birthdays and school functions around her so she can be involved...because I do love her and don't desire for her to be lonely.
So, with all of that, with what's be said previously, and MOST importantly HOW YOU FEEL, make your decision and stand firm, go 100 percent with your choice.