I noticed it and I immediately was worried,
I am 13, and I have a lump on the right side (underside and a bit lower down the shaft) of my penis, it's round, somewhat irritated, and it stings a bit if I touch it. It doesn't change if I have an erection or not, but I only noticed it a few minutes ago, the last time I looked it was NOT there, so it happened in less than a day.
It's not connected to the penis, it's connected to the skin, it moves when I move my skin.
I'm really concerned except that it appeared in only a day, I couldn't really figure out what it was and I REALLY need some answers. Like what it may be.

Also I AM a virgin.
And I'm very reluctant of telling my parents because I really don't want to have to go to the doctor if its serious or anything.

ALSO it is about the size of a phone camera, or for somehwat better reference, a penny cut into a square.

ALSO it is red at the tip-- kind of like a bug bite, except it seems quite a bit too big for that! Please help!

OKAY its now turned into looking like it has a drop of blood underneath the skin of the lump.
PLEASE HELP IM WORRIED

It kind of looks like a pimple 2-3 times the size and not as red...
PLEASE HELP!

Tell your parent and go to the doctor

It kind of looks like a pimple 2-3 times the size and not as red...
PLEASE HELP!

ALSO when I'm erect the lump is firmer and hurts more easily.

It could be something as simple as an ingrown hair but the bottom line is you need to have it checked out.

Quit touching it and tell your mom "ma I have a bump on my penis".
That's what Moms are for.
It is nothing to be embarrassed about and it is most likely nothing serious but it should be looked at!

Yes you do indeed need to see a doc or show your father or a male person you can trust, It also could be that it is part of the puberty process you are go through and it may settle down in a while. So don't poke or play with it, you might just need some cream on it .so you will need to see a doctor.

I'm 22, I get lumps on the bottom of my penis shaft. Its caused from excess masturbation or sometimes too much sex (for me). Its nothing serious to me, just a temporary growth, lasts about 3 days. If it is what I sometimes get, Don't irritate it, or scratch it, just leave it and wait for it to go. If it doesn't go after a week, pop in and see your GP or Nurse and they would be able to advise you further.

Don't worry too much about it. If you are really worried, get an emergency appointment at your local doctors.

No one on this site can give you a diagnosis.

Yes, bumps happen all the time, but just because your brothers fathers roommates best friend had a bump and it was fine, that doesn't mean this one is.

You need to see a doctor. There's nothing to be embarrassed about.

This is your reproductive health, don't leave it up to a bunch of strangers on the internet.

Tell Mom and Dad now! Go to the doctor.