My personal ethics would not allow me to do that. It is a choice that I would feel is very wrong and my conscience would plague me for the rest of my life.
My husband was very strongly against having a baby. He has one from a previous marriage, we all get along wonderfully. It was just his choice to not have more and I agreed. Over time, I came to want one of my own and the feeling was unbearable at times. Our talks became arguments and the topic became taboo. We were both sick of me crying.
I can understand why you would feel compelled to do as you are saying, as I've been in that place. However, I love and respect my husband enough that I could not become pregnant without his consent and stay married to him. It would destroy all the things that are sacred to me in marriage. I would be taking the power of choice away from him and changing his life forever. Not okay with me!
All that said, it is your life, your marriage, and your choice. Just be prepared for the spectrum of consequences that WILL occur: good, bad, and UGLY.