10 weeks after finishing course of pen vk. am i safe from developing cdiff?

Do U have symptoms?: C.Difficile is pathogenic in older children ; adults (whose colonic microflora are altered by antibiotics, chemotherapy, salmonella/shigella). C.Diff causes pseudomembranous ; other colitis, complicates inflammatory bowel disease, causes fulminant transmural extension, perforation with peritonitis, toxic megacolon. If sick, get evaluated ; treated. If not, your risks are likely much lower now.

Yes: If you are otherwise healthy, your likelihood of developing c. Difficille enterocolitis is quite low. Unless you have current symptoms, i don't think you should worry at all.