Can showering after intercourse reduce chance of getting pregnant?
No. The sperm needed to fertilize an egg is already inside of you. Although it helps to lay down for about 1/2 an hour after intercourse when trying to get pregnant, getting up and taking a shower after isn't going to keep you from getting pregnant.
If you have intercourse during your ovulation days what is the percentage of your chance of getting pregnant?
Depending on what type/ how much protection, there is usually always a chance of getting pregnant. If only a condom is being used, then it is absolutely still possible to get pregnant (the condom can break). The more protection used, the lesser the chance of getting pregnant, BUT the only way to prevent pregnancy 100% is not to engage is sexual intercourse at all.