Lying flat after sex has little effect on pregnancy and there is no specific time limit.
There is no specific time limit on how long you can lie down after sex during the preparation period, and it is important to reasonably calculate the time of ovulation and have intercourse every other day to increase the success rate of conception.
Ovulation refers to the time within a week before and after the day of ovulation, women with regular menstruation, in the menstrual period forward 14 days for the day of ovulation. You can also start on the 9th day of menstruation and do ultrasound every other day to monitor the follicles, and arrange intercourse when the follicles are close to maturity.
It is recommended that couples preparing for pregnancy go to the hospital for a pre-pregnancy eugenics health checkup to assess whether their bodies are fit for pregnancy. Quit smoking and drinking, develop good living habits to maintain good health, avoid prolonged exposure to radiation or pollution, get out of toxic and harmful work environments, and women should start taking oral folic acid from 3 months before the planned pregnancy to prevent neural tube defects.