My brother and I are very close in age, and my mom has told me that when she was pregnant with my brother she looked at me and thought that I was so old and mature and that I would be able to help her out so much. Well when he was finally born, she realized quickly that I wasn't going to be as much help as she thought. How could I at 18 months old?
She has told me that she wouldn't change anything for the world, but when its my turn to have kids, she would recomend spacing them a little further than she did.
However, I love being so close in age with my brother. We always were close (as we got older). I thought we would kill each other when we were younger though.
I think that if you are going to be the primary care giver then you should be 100% ok with the idea of having 2 very young kids. If you think it might be to much, then I would talk to dh about your concerns and maybe come to an agreement that you would like to have more kids, but would just like to wait a while.