Well OK, maybe 101 was a bit of an exaggeration but follow these suggestions and you will stand a good chance of not getting pregnant...
Don't have sex without a condom - If you do you will not only stand a good chance of getting pregnant you will also be at risk of catching a nasty sexually transmitted infection!
Don't miss a daily contraceptive pill - It is advisable to use condoms and the pill together. However, if you do just use the pill you will risk pregnancy if you forget to take one or more. If this happens, you must use condoms and the pill for the rest of the pill cycle.
Don't take your daily contraceptive pill at irregular times - This lowers the effectiveness of the pill so you should always take it at the same time each day.
Don't have unprotected sex during your period - A lot of people think that whilst you are on your period you can't get pregnant... that is totally wrong! So work on the assumption that there is never a "safe time" to have unprotected sex.
Don't think pulling out before ejaculation can prevent pregnancy - Treat a penis like a loaded gun... it's always dangerous, so protect it with a condom at all times!
Don't think that it's OK to rub an unprotected penis around the outside of a vagina - It's still possible for some sperm to get inside.
Don't allow either partner's fingers to touch his penis then enter her vagina - even before ejaculation some sperm can be present.
Don't let fingers that have touched a penis touch the outside of a condom - sperm could be transferred to the condom and then get inside the vagina.
Don't leave a penis inside a vagina too long after ejaculation - It is always best to withdraw straight after ejaculation as a common cause for condoms coming off inside is when the penis has gone down and the condom is no longer a tight fit.
Don't have sex if you think all this is too much to remember! - It's easy to make a mistake in the heat of the moment so make sure this knowledge is second nature so you don't have to think about it!
Never underestimate the power of sperm... a small drop of semen on the end of a man's penis carries enough sperm to fertilise all the women in Columbia! In case your geography is not that hot, we are talking around 18 million babies!