What Causes Sore After Masturbation?

hello i am a young teenage girl 13 years old and i am extremly worried i masturbated and after i did that i got these things that look like sores but i am not sure but they arent blisters it just looks like a sore that comes out for no reson my mom know about this and i told her EVERYTHING she said it was probaly an allergic reaction or i was allergic to something but i dont think thats what it is please help do you know what it could be?