Femidoms are less readily available than male condoms and are also more expensive. Most pharmacies/drug stores/chemists should stock them though.
a femidom is a condom for girls
Boots or other chemists.
If you are a male, use a condom. A female, Use a femidom. Or you can take pills to stop the pregnancy.
Well, it's probably 'doggy style' that's most effective. However if you do not a penis to be placed into the anus, you should just try it with both of you lying down, the male on top going in and out of the virgina. If that's not very effective try having sex with the male lying down and the female sitting on him with her virgina on his penis. Remember, use birth control (condom, femidom etc.)
No it cant because the womens body already has acids in it to protect itself from bacteria, so the yest infection will make sperm even harder to survive because the infection will eat away also at the sperm.