Credit Card Probate Claim

[t1r7]

I probated my father's estate over 4 months ago. The assets were simple, less than $15000. There was a claim put against the estate for a credit card. I put a notice to creditors in the paper (well, the court did) and gave until a certain date. this claim was filed on that final day. Am I responisible for paying this? If I disallow it, what might happen?