My husband wants me to have an abortion...But I dont know if I could go through with it?

My husband was injured in Afghanistan in February we already have 2 boys ages 3 and 1. We found out monday(the day after our wedding anniversary) that I was pregnant. I have not even been to see the doctor yet I don't even know how far along I am. My boys are a handful and we are under stress with my husband being in and out of the hospital having more surgeries and Physical therapy to learn to walk again. He says we can not handle another baby right now that there would be too much stress. I feel it has happened for a reason. He has suggested an abortion numerous times and I have done the research I honestly don't think I can go through with it. Can anyone give me advice as what to do how would you feel in this situation?