white bump on back,,during pct???

hey quick question for ya,,im just being a parnoid bit*h, but i take my body verrry serious. i just finished my cycle 2 weeks ago and for some reason i got a funny looking bumped raised on my middle-right back..it is a shade lighter than my skin and looks like a huge pimple..it also doesnt hurt and i cant even feel it when my GF touches it..it is def. just in the skin and not on bone..its about the size of your pinky finger nail, and raised just a bit..but is no way a pimple.its just chillin there and im not sure what it is....if anyone gets these or has one.. could you let me know what it is? thanks

better pop that thing..i had one on my back in 6th grade and had to get it cut out..i forgot what they are called...like infected pimples.