The safe period of extracorporeal ejaculation generally will not be pregnant, but can not absolutely completely exclude the possibility of pregnancy.
Safe period of time, the general follicle can not mature, or has been ovulated, this time sex is not much chance of pregnancy, coupled with extracorporeal ejaculation, the chances of pregnancy is even more reduced.
But ovulation is regulated by the pituitary-hypothalamus-ovarian axis, when the sexual urge, due to hormone levels, the follicle is likely to rapidly mature and discharge within a few hours. Even with extracorporeal ejaculation, when a healthy sperm meets an egg in the prostate fluid during sex, the possibility of pregnancy is not ruled out.
If there is no need to prepare for pregnancy, it is advisable to use effective contraception, such as condoms, every time you have sex.