sir, am 23 year boy,healthy.70kgs,i used to watch porn twice or thrice a week and manturbate 3 to 4 times a week.every time i mansturbate there was no problm till nw.but last time wen i ws mansturbating i ws in full zoom n started to jerk very hard n ws hitting th testicles very hard,n wen it came out after the sperm came litle blood came out ,there was no pain or burning sensation,am feared tht something is wrong or wat,after 2-3 days am heal n healthy.is it common or there ny problm.plzz help me out of this problm.