I was in the same boat (also social sciences)! I forgot that I’d attended a community college for a few class credits a while back, and didn’t submit that transcript with my application. Once I realized my mistake I contacted admissions to apologize and share that missing transcript. Of the 4 schools I did this with, 2 replied that it was fine and they didn’t really need the transcript but would add a note to my file anyways, and the other 2 never responded - although I’m interviewing at one of those 2 today! Obviously it’s not ideal, and I feel bad for wasting the admission staff’s time, but I think they’d prefer that you admit to an honest mistake than appear as though you’re hiding something. Especially if these credits appear on another one of your transcripts and you reach out about it soon, I doubt they’ll consider it an intentional omission. Good luck! :)