Precisely, and it should be added that all science says is "this is the best model that we have at this time with the tools available". It is likely that as our understanding of the universe grows, new phenomena will be discovered.
The point is that we don't know what we'll discover in the future, but we can use our current model to guide us. If the current model turns out to not be accurate, append it or replace it with a better one.
Nido, what it feels like you are driving at is that a supernatural force is required somewhere (if I am wrong with that assumption, please correct me). However, because this force is supernatural, we by definition have no means by which we can understand it, as our observations are limited to the natural world. If, somehow in the future, we were somehow able to detect a supernatural thing by something we could observe, then absolutely science would amend itself appropriately. But until then, we must work with the tools we have, which right now are confined to the universe that we live in. Making baseless assumptions about the universe at best does nothing constructive for our understanding, and at worst would hinder or destroy our progress.