Hello Bellvivienne
There are quite a few possibilities as to what the diagnosis may be. The fact the you have had the area biopsied is very reassuring as general guidelines suggest that oral ulceration that does not heal either spontaneously or with dental intervention after a period of 2 weeks should be considered to have a more significant cause.
However the soft palate is not the most common site for oral malignancy, and the fact that you are female, do not smoke and the ulcer is very sore are all positive signs.
The best advice I could give would be to say not to worry at this stage - though I realise this might be easier said than done. As soon as the biopsy results are available, a definative diagnosis should be able to be reached and appropriate treatment initiated.