I totally understand why you would be worried. I would be too. If these are itchy they may be ring worms. This can be treated really easily but you would need to go to your doctor to get a prescription. Now if these appear when engaged in sex they can be swollen sweat glands. The best thing to do is to go to the doctor. I would be worried too but it is best to know what you are dealing with so you can get rid of them or at least know what they are. Here's a link that has a discussion like this.
I Have Knots By My Scrotum They Don't Hurt But If I Push Hard They Do Hurt The Sometimes Come And Go I'm 17 Should I Be A Little Worried?
Could be jammed up sperm I guess, but you probably should have it checked out, you don't want to mess around with anything like that, think about Lance Armstrong...