There are 3 very related answers to this question:
Conception
- Conception requires one egg and one sperm.
- Only an egg can be fertilized.
- Once one egg is fertilized and implants in the uterine wall, that's it-- no other eggs can be released; no other sperm can create fertilization because there is no longer an egg to be fertilized.
- Once implantation occurs, hormones switch to pregnancy hormones specifically to support the new fetus. There will be no other egg released while pregnancy hormones are high, e.g. through the entire pregnancy.
Female Fetus
- Every mammal, including humans, must reach sexual maturity before the first egg is released. In humans, this occurs in puberty. Sex hormones are NOT present before then.
- A fetus does NOT produce any egg-- it does not ovulate because there are no sex hormones released until puberty.
- NO FETUS at any point in a pregnancy can "get pregnant"!! Never! Never ever ever!
Sexual intercourse with a pregnant female:
- Since the fetus has not reached puberty (which occurs between 11 and 13 yrs old on average), the fetus can never, ever be impregnated.
- When a female is pregnant, the body adds protections to the fetus. The main protection is that the fetus is enclosed in an amniotic sac with special amniotic fluid. No sperm can ever poke through that sac. Ever!
- The cervix in pregnancy has a "mucous plug" so bacteria and sperm cannot get through.
- The cervical mucous changes during pregnancy and any sperm, IF any could possibly get through the cervical "plug" of mucous, will simply die. Again, there is no new egg released when a woman is already pregnant.
- Lastly, no male or males can ever make a woman pregnant (newly pregnant) when she is already pregnant-- it is just NOT how it works! One pregnancy only can be... even if she is pregnant with more than 1 fetus.
- And again, a female FETUS can never get pregnant! Biologically impossible!
