The important thing for the visa is not how much time you've spent outside the UK, but that the UK remains your main home and that you have lived with your husband for the entire time (whether that's in the UK or not).
Now, there are exceptions to living together for the whole time if he is on military deployment, because you don't have a choice in being apart during that time... so that shouldn't affect the next visa.
I think you would probably be fine to visit the US for a couple of months while he is away, because it wouldn't be possible for you to live together during his deployment anyway.
However, if he wasn't deployed abroad and you just went back to the US for a few months while he stayed in the UK, that could be an issue, because you would have been living apart for several months of the visa, without a good enough reason for doing so (i.e. a good reason would be that he is working/deployed overseas).