If it was on the outside of the sack and not on the ball then i wouldn't worry. It sounds more like it was a zit, or ingrown hair. But consult your GP if you're still worried.

I am not a doctor and I have no medical qualifications.  That said, I agree with [@Ben1567]‍ 

If this was inside the sack then no amount of squeezing would produce any blood or pus. So the fact you've produced pus (that's the white/yellow liquid) is a pretty clear indication of a minor infection, such as a zit, boil or ingrowing hair.  It's also common to get lymph (the clear fluid) and blood mixed in with the pus in such situations.

Most likely you've cleared the infection now and it will get better on its own.  Nevertheless, check it daily and if starts getting painful, or it starts to get bigger, or you're simply still worried then see a GP.  But be reassured there's no reason to think this is testicular cancer.