The simple answer is we don’t know. Consider this verse from Mark 16:16:
“Whoever believes and is baptized will be saved, but whoever does not believe will be condemned”
It is clear what will happen to those who believe and are baptised. It is also clear what will happen to those who don’t believe, whether they are baptised or not. But nothing is said here about those who believe but are not yet baptised. The reason is, presumably, that those who believe will be baptised, so in principle there shouldn’t be anyone who believes but isn’t baptised. But in practice we know that things are not so immediate. It takes time to come to a full realisation of the gospel and to feel ready for baptism. And, because of sheer practicalities, people are rarely baptised in water the very moment they ask for it.
I think we need to understand that baptism is not magic. The water itself does nothing; it is a symbol of your change of state. I find it improbable that the merciful Lord Jesus would reject one fully devoted to him for the sake of water. So whilst I believe that the symbol of baptism is essential, I do not think we should worry that we might be condemned because of circumstances, rather than lack of belief.