Lump on penis (cancer ? Cyst? Ingrown hair? Sti?)

hey, so Ive noticed this hard lump on my penis, weirdly enough i didn't notice this until yesterday and today it changed it's tone in terms of more redness on the middle and little pain when i touch or squeeze it. ive tried to squeeze it Incase its pimple like lunp but nothing happened other than slight lowkey pain. in addition i do know i need to seek medical advice to find out but meanwhile does anyone with knowledge may know what it is by looking at the pictures ? im very skeptical on sexual disease because my sexual life only consist with my gf and thats all, as we were previously tested negative for anything.

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closest guess I have is syphilis.. but it has to show up in blood work

to update the lump has exploded and white / blood came out so it may be pimple or infection in some sorts. still not sure but will have to get checked for sure. lump is much smaller now but i can still feel the hardness round it.

updated picture of the lump which is now still visible and noticeable but smaller in size and little harder on the skin where the lump was before it popped off.