Hi, My 3 Yo Just Finished Antibiotics For School Sores

Hi, my 3 yo just finished antibiotics for school sores which were mainly on one side of his mid section, they are looking pink and like they are healing but he just told me something hurt on his inner thigh! I had a look and there is a really small sore, looks like either an ulcer or a popped blister but it is not red, it's just the same colour as the rest of his skin! Could it be more schools sores coming?