Having too much sex: Yes, this is actually possible. Having too much sex is great but it may lead to fatigue. Which might hamper your ability to have sex exactly when it will help you get pregnant -- when you are ovulating
Not having enough sex: If you think that not having sex for a while and then trying to get pregnant will somehow help preserve your sperm or make them stronger, then think again. No such thing will happen. But having sex regularly, especially when your lady is ovulating will help you get pregnant faster
Sticking to the same position: There are a number sex positions that are great to help you get pregnant faster but what you need to remember is that any sex position you try, be it missionary, doggy or something more risque, you will still get pregnant. A man's sperm will still reach your cervix and your egg, no matter what you do.
Mis-timing your ovulation: Women use a number of ways to gauge when they are ovulating (the time when the egg is released into a woman's uterus); the calendar method, using ovulation strips or measuring their basal body temperature. But if you miscalculate when ovulation occurs you might miss that golden period for conception.
Having sex the day you ovulate: If you thought that having sex on the day you ovulate (based on your calculations) is a good idea, think again; especially if you are calculating your date of ovulation based on the calendar method. This is because a woman's ovulation fluctuates month-on-month and is pretty hard to predict. The good news here is that while an egg survives for only 24 hours in a woman's womb, a man's sperm survives for two to three days (after ejaculation) in a woman's cervix - making it a good idea to have sex regularly.
Tip: An indicator of impending ovulation is when a woman notices a clear thick discharge. This usually happens a few days before ovulation -- helping you time yourself better.
Using lubricant: Lubricants are often harmful to sperm and do not allow them to swim towards the egg with as much efficiency as it would normally. If you are looking to get pregnant, avoid using lubricant, and if you simply must, then use one that isn't harmful to sperm.
Rushing to the conclusion that you are infertile: It takes healthy couples at least six months of trying to get pregnant. So if you haven't conceived yet, don't bring yourself down just yet. Remember keeping your woman happy is the best way to improve your chances of getting pregnant.
Not going to the doctor in time: On the flipside, there is also a common belief to avoid going to the doctor. This could be bad in the long term as you might be ignoring larger problems that need immediate medical attention. The thumb rule to follow is if you have not been able to conceive even after over six months of trying, it's time to visit a doctor.
Neglecting your general health: This is probably the worst thing you can do. Not only do both you and your partner need through medical check-ups, it is even more essential when you are trying to get pregnant. Health issues like high blood pressure, PCOS (Polycystic Ovarian Syndrome), obesity, diabetes, ovarian cysts, etc. are common health problems that can affect your ability to get pregnant.
Blaming the woman: When a couple is unable to conceive, it is a common tendency to blame the woman for being infertile. But often, a problem in conception is a sign that something is amiss - in both, the man or the woman. Moreover, blaming your lady for not being able to have a baby will only lead to depression and fights which can make it even more difficult for her to conceive.