Hello,
I was just thinking about a solution for your case, I think that something like that is possible.
How did you define your dataset ? Are you using data.Dataset class from pytorch ? If yes, you should be able to specify whatever you want. I mean, you can do somehing like:
class mixedDataset(data.Dataset):
     def __getitem__(self, index):
           return your combined_data

    def __getlabeleddata_(self,index):
           return your labeled data 

and after you can iterate through your mixedDataset and calling your getlabeldata function to get the labeled data.