It isnt big, its like the size of a normal pimple. Its white and i can squeeze it like a pimple and stringy white puss will come out. Then it wil be like there but not there at the same time like its jist waiting to puss back up, and then it does and i can repeat the process. There isnt any pain before or after i squeeze it. Ive literally had pimples do the same exact thing but not come back. Only squeezed it three times. I originally thought it was a sebaceous cyst but im worried its an std now. Any help?