Is it easy to get pregnant from external ejaculation on the first day of ovulation?

In general, the probability of pregnancy from withdrawal (coitus interruptus) on the first day of ovulation is relatively low, but it is not completely safe and there remains a risk of unintended pregnancy. The specific analysis is as follows:

On the first day of ovulation, the egg may not yet have been released or may have just been released, so the likelihood of fertilization at this time is inherently low. Additionally, with withdrawal, fewer sperm enter the vagina, further reducing the chance of conception. For individuals who do not currently plan to have children, this method serves as a relatively simple form of contraception.

However, withdrawal is not a reliable contraceptive method. Pre-ejaculatory fluid may contain small amounts of active sperm capable of causing pregnancy. If ovulation occurs earlier than expected or if sperm survive longer in the female reproductive tract, fertilization may still occur. Furthermore, improper timing—such as failing to withdraw promptly before ejaculation—can increase the risk of pregnancy.

For those who do not wish to become pregnant, it is recommended to use more effective contraceptive methods, such as condoms or oral short-term contraceptives. It is also important to understand one's own ovulation patterns and avoid relying on unsafe methods like withdrawal, thereby minimizing the risk of unintended pregnancy and protecting reproductive health.