Can I prevent pregnancy by calculating the safe period?

After marriage, she was very happy all day long and rarely contacted me anymore. Until late one night, she suddenly called me. Her tone was strange, hoarse and hoarse, as if she had just cried, and she refused to speak no matter how much I asked.

    I had to get up and rush to her new home.

    Her husband opened the door for me with a livid face. When he went in, he saw that Ning Ning was already in tears. As soon as he saw me, he cried even more and choked up, and told me: I might be pregnant, and it's all his fault! So that was it, I temporarily relaxed and asked them what happened. After asking, I found out that Ning Ning had been feeling poor appetite and dizziness recently, and had taken a lot of medicine, but she just found out that she was pregnant today! It was also difficult to save this baby because he was on so many medications. I find it very strange that Ning Ning is a doctor, how could she not know about her pregnancy?

    Ning Ning told me with sobs that her husband went on a business trip not long ago, and she happened to have her period while he was on the business trip. When her husband came back, her period had just ended, so she did not take contraceptive measures, because no matter how you calculate it, the day after your period just ended should be safe. At this time, Ning Ning's husband interjected: "I'm not afraid of your jokes. I was very worried that Ning Ning would suffer, so I had to take measures. But Ning Ning insisted that it was okay, and she was a doctor, so she couldn't be wrong, so I listened to her, but the result, alas..."; Ning Ning became even more angry: "I didn't do this for you! They always say that condoms are like wearing a raincoat in the shower. You don’t even feel anything on your wedding night. I’m not here to make you feel better! ”;

    Ning Ning’s story is by no means a fabrication, nor is it accidental. There are many female People like to use the method of calculating the safe period and using condoms to prevent pregnancy, thinking that this is foolproof, but in fact it is not safe at all. Like Ning Ning, when her period has just ended, it is not uncommon for her to ovulate due to excessive excitement due to reunion with her husband after a short break.

    Most women have a menstrual cycle of 24-32 days, with ovulation occurring on days 12-18. If the egg fails to be fertilized 24 hours after ovulation, the egg cell will die on its own. sperm Generally speaking, eggs can be fertilized within three days after ovulation, but there are reports that sperm still retain the ability to fertilize after one week of sexual intercourse.