There is also the possibility of unwanted pregnancy when using condoms for intercourse. When this happens, it is mainly due to the following reasons: 1. The patient does not get the whole contraception. If the patient does not use a condom before ejaculation and chooses to use a condom only when he is about to ejaculate, there is a possibility that prostate fluid will flow out before ejaculation, which will contain sperm, so there is a possibility of conception. 2. Therefore, it is important for men to use condoms during intercourse, and to check if the condoms are broken or fallen off after intercourse.