Turtle had a bump

by christy
(philadephia, pa, U.S.)

Hi,

Last week I noticed a sphere shaped bump on my turtle's neck and it began to get brown spots on it and then later the whole top of it turned a yellowy color (like dry pus?) and yesterday I noticed that the bump popped.. i was planning on taking him to the vet when i get the time and money... should i still take him? what do you think this is