QuestionCan I kill sperm by me just by simply urinating?
While urine is acidic and will kill sperm, urinating after sex will not kill the sperm inside you because your urinary tube is not in your vagina. It is a separate opening just above your vagina. In addition, when a man ejaculates in a woman, he puts the semen at the back of the vaginal tube, near the cervix and the uterus. No urine comes close to that point.
The problem is that you are trying to find a way to avoid the consequence of a sin. Having sex without being married to your partner is a sin. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4). Instead of trying to avoid the natural result of sex, find a man worthy of marrying and then you can enjoy sex without having to worry if children might come as a result.