Some couples are struggling to get pregnant, while others become happy (or, sometimes, not so happy) parents in a split second. Even when it seems that they do everything right, use all the proper protection, take pills, undergo certain procedures, and know exactly how all this child-conceiving stuff works, they can get a sudden surprise in the form of the late period and a positive pregnancy test.

Sometimes it happens because the couple isn't careful enough, but at other times it just happens. Perhaps, it's just their destiny to have a baby at this very moment. Nature just finds a way, these two cells meet, and it looks like no measures can stop the baby from coming into this world. Let's see how it all works and what unexpected, not so common ways can make a woman pregnant.

17 "They're Only 97% Effective," Rachel Said

Remember Ross' reaction when Rachel said that she was pregnant? He was utterly shocked because, as he said, they used protection, and he was sure that everything would be fine. But no, in fact, in 3% of the cases, this kind of contraception doesn't work. According to Baby Gaga, it mostly happens if it's expired or damaged. And yeah, Ross,  they put it on the box.

16 Using Your Teeth To Open The Dang Thing

Opening your latex friend with your teeth in the heat of the moment is one of the sure ways you can damage it. Mary Jane Minkin, MD, from Yale School of Medicine says that if you use your teeth or scissors, you may easily break it, so you should always open it with your fingers on one of the notches. It's not that hard, believe us! Certainly easier than raising a child...

15 Even If You Have Your Undies On

Even when you fool around with your underwear on, it's still not 100% safe. We mean that pregnancy can happen and, if you don't plan it, it can become an unpleasant surprise for you. How can it happen? According to Dr. Minkin, if the man spills something on his boxers and this stuff gets onto the woman's undies, the boys can get in there and start a new life.

14 Getting Pregnant From A Finger? Yeah, It's Possible

Finger fun is great, but if he just finished and has some of his stuff on his fingers left, it's better to go wash his hands or, at least, wipe them with a tissue. Of course, in the heat of the moment, it's easy to miss it, but, according to Elite Readers, it can cost you the nine months of pregnancy and child-raising duties. So better be more careful.

13 You Can Get Pregnant While Already Being Pregnant

I know, it sounds horrible, but it's actually possible to get pregnant while already having a bun in the oven. Sure, it's super-rare, but it happens. Dr. Minkin explains that if a pregnant woman keeps on ovulating and doesn't use protection (who uses it during pregnancy, after all??), the second fertilized egg can implant and a second pregnancy may happen.

12 Vasectomy Isn't 100% Effective

Vasectomies are pretty effective, but they aren't 100% effective. Dr. Minkin explains why you can still get pregnant after he had the procedure: "Vasectomies don't take effect immediately, so the urologist recommends having a follow-up analysis a couple of months afterwards to see if he is totally clear." So don't rush into things and don't throw all the protection away right after the procedure.

11 Just Like Tying Your Tubes

Tying your tubes doesn't give the total anti-pregnancy guarantee, as well. According to Dr. Minkin, although it's generally one of the best ways to prevent pregnancy, there is a 1% failure rate in this procedure. Statistics on Comprehensive Gynecology say: "Failure occurs in about five women out of a thousand within a year, going up to 18 women per a thousand after ten years."

10 Even Your Pills Aren't A 100% Guarantee

As you have already understood, no contraceptive method works in 100% of the cases. All of them can fail you, even though some do it very rarely. When it comes to pills, even they have a 1% failure rate, Pulse says. Taking them at irregular times, gaining body mass, eating certain things - all this can decrease the effectiveness of the pills and result in an unplanned pregnancy.

9 Morning-After Pills Don't Always Work, Either

Emergency contraception usually works good, but even it doesn't guarantee that you won't get pregnant. Even if you take the pill within the 24-hour timeframe, as it's said in the instructions, it's still only 95% effective, Dr. Minkin says. Besides, the longer you wait, the less effective they become. If you take the pill more than 72 hours post-contact... well, let's just say that you don't have to take it already.

8 Using An Oil-Based Lube

Using the lube is often a good idea, but before buying one, you should read the label and ensure that it doesn't contain any oil. According to TheTalko, oils can damage the latex in a way that creates tiny holes in it. As if it doesn't present enough danger for the couple who doesn't want kids, oil compounds can make the whole thing break. So opt for water-based lube instead.

7 You Can Get Knocked Up In The Tub

This one isn't really likely, but it can happen. If you and your partner are fooling around in the tub and some of his guys get into the water, there's a small chance that they will eventually "swim" toward you and, well, decide to make a home inside your body. After all, as Baby Gaga says, it takes only one to make a baby!

6 Getting Pregnant With Aunt Flo Is Town Is Possible, Too

Some people say that menstruation is the safest time and there is no way to get pregnant while on your period. However, it's not 100% true. While it's unlikely to conceive during menstruation, it's not completely impossible. Minkin says that the boys can live inside you for up to 5 days, so if they stay there before the O-time comes, they can easily do what they are meant to do.

5 Breastfeeding Isn't Contraception

If you think that you can't get pregnant while breastfeeding because you don't have your period and hormones suppress your ovulation, you're wrong. This so-called natural contraception doesn't always work and, according to Baby Gaga, it has a 2% failure rate. Believe us, you don't want to have another child so soon, so better take other measures to prevent pregnancy.

4 Being The Little Spoon At Night

Yes, even such an innocent thing as naked spooning or cuddling can get you pregnant. If the guy has some of his stuff on his body or if it gets onto the sheets, it can easily travel into your body. Remember that, according to Baby Gaga, the boys don't die immediately after hitting the air, although they do die rather quickly.

3 Some Natural Medicine Can Impact The Effectiveness Of Your Pills

Natural medicine isn't always safe and beneficial. Let's take St. John’s Wort, for example. Baby Gaga says that, although it's rather effective in treating certain forms of anxiety and depression, it can actually decrease the effectiveness of contraceptive pills. It happens because this herb may impact the way your body handles estrogen. It's just an example because other herbs can do it, too, so before taking them, consult your doctor.

2 You Can Get Pregnant During Non-Ovulation Days

As we've mentioned before, your partner's cells can remain inside you for about five days. It means that relying too much on the calendar method isn't a good idea. TheTalko says that even if your timing is just a little bit off, it can still lead to one of them waiting long enough to implant and turn into a beautiful baby. Are you ready for it?

1 If You Forget To Leave Room At The Tip

Sure, when you're all passionate, it's easy to forget to check that some room is left at the tip of your latex friend. But if you don't do it, keep in mind that the consequences can be dire. As per Elite Readers, it can result in part of the stuff spilling out from the sides. You get what it can lead to, right?

Sources: Baby Gaga, Buzz Feed, Pulse, Elite Readers, The Talko