Your prayer and wudhu are all valid as bleeding doesn’t affect your purity and prayer unless it is from the private parts.

Today when I had finished praying the duhr prayer, I noticed a tiny bit of dried blood on my nail and the skin right next to the nail. I do not know when this blood got there. I did not see or notice it while I was making wudhu so I don´t know if it was there before or after I made the wudhu. Is my wudhu and prayer valid or should I repeat it?