Hi Rebekah,
If you can give some answers below maybe we can help:
1- Are you able to see your data at PSA level? You can check this in the PSA table. Just double click your datasource in RSA1 and from the menu go to Goto-->Technical Attributes. There you can see the PSA table name. You can also double click and reach to the table directly.
2- Is your DTP a delta or full load?
3- Do you see any Request in your infoprovider after you run the DTP? (Check this by right clicking your infoprovider and choose "Manage" from the menu.) If yes, what is the number under "Added Records"? (Probably 0, if you see a Request)
4- Do you have any "Filter" in your DTP? (Check if there is any Check sign next to Filter button in the first tab of your DTP)
5- Finally, do you have any Start or End routine in your transformation?
You can add screenshots if you want to, that may also help to analyse the issue.
Thanks,
Klamox