A uterine air embolism is technically possible, but exceedingly rare and unlikely. It would require a combination of high air pressure, trajectory of flow, and a very relaxed cervix. (However, health professionals strongly advise against sexplay with air jets, hot-tub jets and the like, due to that slight possibility.) Normal flatulence that occasionally enters the vagina as a result of sitting at a particular angle or "clenching" cannot possibly create enough pressure to enter the uterus, nor can sexual intercourse - unless the cervix were dilated due to advanced pregnancy, labour or a laminary insertion prior to a D&C procedure. A woman in either situation would likely be paying rather more attention to her bodily comfort.
How do I know all this? I used to work in an OR, and have fielded this question more than once from an anxious patient. The only uterine air embolism I have ever heard of in reality was a post-delivery incident, involving a woman's cervix that didn't contract as quickly as normal. She was cathetered, and the gas passed without harm.
DEPENDS ON WHAT YOU MEAN BY WEIRD? HOW CAN YOU HEAR IN THE UTERUS? IF YOU MEAN STOMACH GROWLING AND GAS, THEN YES.
allows blood flow to pass and sperms to enter
The fetus is in the uterus and when pregnant there's a mucus plug closing the entrance to the uterus so semen or anything else can not enter when you are pregnant.
No. They can not enter the uterus without risking miscarriage. There is also no ovulation during pregnancy.
Sperms can not enter the uterus after you get pregnant. They may remain in posterior fornix of the vagina and will die eventually.
The ovum that is released at ovulation enters the fallopian tube (oviduct). If it were to be fertilized, it will then start dividing, forming an embryo which will eventually enter the uterus.
Some women feel when the man ejaculates semen and others don't. if you mean when the actual sperms enter the uterus you can not feel it and def not if one enter a egg.