Hi B.,
To me, it does not sound like you have completely decided if you and your husband should do something permanent yet. Your babies are still very young, demanding and time consuming. I would not make any permanent decisions util they are a little older, if I were you.
I am a mother of four children...the oldest and youngest are 16 years apart. We had two children (19 months apart) then we waited 10.5 years then another one...then 4.5 years later we had one more. My husband had said he did not want any more children after the first two...thank goodness we did not do something permanent because I cant imagine my life without my two younger children. WE love kids and we are both so glad that we had the last two. People always think that our last two were "surprise babies", but it was the first two that were unplanned! But, I would not change any of it for anything...
If you think you may get to a point when you might want another baby, do not do any thing permanent. A few more years of the pill will not make that much difference in the long term things. Give you and your husband a chance to let the babies grow up a little and then you may decide to have one more. If my husband would have had things his way, we would have only had two. My husband changed his way of thinking when all of our friends and siblings were starting their families..(that was when I told him I was finished taking the pill----if he was done, he needed to go and get a vasectomy). Well, he decided that he liked having kids and wanted just one more...well, when our 3rd one was about 3, he figured he would have been like an only child, so he asked me if I wanted another one...and when I was pregnant with her, I KNEW that I was finished having children...now I am waiting for grandbabies!
Best of luck with your decision....
T.