When I was doing sex with my partner suddenly condom was broken I removed immediately and the next day I got red spots on my urethra is that indicate I got STD
Good evening
Without a picture it is hard to say but a STD would not come up that fast. What you may have is Balanitis which is a irritation cause by sex or masturbation
Get a fungal cream and it should go away. No sex till it is gone because you will just irritate it more
Take care…Ken