No, the purpose of a condom is to aid against transmitting dieases and to trap seamen as to not impreganate the woman. Unless you feel the condom break after a woman has come due to excess pressure, there is no need to change it.
If there are sperm in the condom the woman could get pregnant.
You can never be to careful so you should always use the pill or a condom
As for all alien elements, it should not be there. (Sometimes it stay behind if the man does not pull out after ejaculation, but this is not common) If you have latex allergy or rubber allergy and the condom is made out of what you are allergic to, then this can cause inflammation leading to severe itchiness or even pain. If having sex with a man wearing a condom and you get problems, then change to another type of condom next time. There are condoms made that are not considered allergenic. Normally the woman cannot tell between a regular penis and one that is covered with a condom. There should be no difference in the sensation to a woman.
No
Yes she can and this is why the so called pull out method is not recommended and you should always use a condom.
YES
The condom is for the male and can only be worn on the penis. The woman can use a barrier if she so desires. It is worth knowing 1 in 7 condoms fail.
A male condom is placed on a man's erect penis. A female condom is inserted inside the woman's vagina.
it means that you had relations with a men and that you didn't use a condom
You can't get pregnant unless the condom breaks or is used wrong. Not all condoms have lube but works just as well as any other condom. If the woman is lubricated enough naturally you don't need a lubricated condom. It's not the lube that protects you from pregnancy.
Universally, to make a woman pregnant requires you to have sex with her. Do not pull out at the end, and dont use a condom or oral prophylactic like "the pill".
Condoms don't prevent pregnancy by killing sperm, they prevent pregnancy by capturing sperm cells when the man ejaculates. Once a man ejaculates in a woman's vagina without a condom there is nothing a condom can retroactively do to prevent pregnancy. Best to put on a condom before intercourse. If you have ejaculated in a woman the best way to prevent pregnancy is the "morning after pill". It's a dose of hormones that can prevent ovulation.