Lump on Penis shaft

I recently found a lump on my penis and it has begun to worry me. I found it a few weeks ago and I realized that it has gotten a bit bigger. It is slightly red, but it closely resembles the color of my skin. It is on the shaft, right around the middle.

I am not sexually active. I am a virgin who has never had any sexual contact (no vaginal, oral, anal, etc.). I am 18 years old and I am uncircumsized.

I need some advice on what I should do. I have finals until May 11, but because I noticed a slight increase in the size, I'm getting a bit paranoid. I'd like to finish my finals and then go see a doctor, but I do not know what to do. I live on campus and I could ask my parents to take me to the doctor since I live only about 45 minutes away, but I really, really need to study. I would go to the health center, but I decided to decline on the supplemental insurance because it was too much money.

Please help! I'm really scared now and I don't want to tell my parents now because it will only worry them. My sister is a cancer survivor, but that experience put my parents (especially my mom) through so much emotional hell. I'd rather tell her after my final is over, but could it be too late?

[destructzero]

Oh, and some more information. It does hurt a little when I accidentally touch it. (Either while urinating, changing, rubbing against my pants, etc.)