*I am not a medical professional. The following is from my experience, so please don't take anything I write as medical counsel, that should come from a doctor.
You should try for a year before going to the doctor for help
If you try a couple cycles and nothing happens the woman should do ovulation tests to make sure shes ovulating. If she isn't ovulating there is no sense in trying on your own, it won't happen. Go to your OBGYN. If you are ovulating then sure, try for as long as you want on your own, then go to the doctor if you feel like things aren't working right or its taking unreasonably long.
You'll get pregnant if you aren't on birth control
This one caused a lot of frustration for me. I always thought that as soon as my husband and I wanted to get pregnant I would go off birth control and BAM, I'd be pregnant. Thank you every health class ever for drilling in "if you don't use protection you WILL get pregnant". Sure, if you have a regular period, ovulate, have sex at the right time and have a partner with their own fully functional reproductive system, then yes, you will probably get pregnant without having to try too long. If any of those components aren't working properly then simply not taking birth control isn't going to do the trick. DO NOT BE DUMB AND TAKE THIS AS ME SAYING "DONT TAKE BIRTH CONTROL". I could go the rest of my life not taking birth control and never get pregnant, and at the same time I've had friends who missed one day of birth control and became pregnant. I am definitely a proponent of birth control/protection.
People who need fertility help need expensive treatments like IVF
To get pregnant with Aurelia all it took (other than time, tears and my regular surgery) was a $12 prescription of Clomid. With our other attempts however it did take thousands upon thousands of dollars.
Relax and you will get pregnant
Sure, stress is not helpful in getting pregnant. Stress can negatively influence all kinds of body processes, but not putting enough effort in is more detrimental if there is something not working properly.
30 is the new 20
Socially, sure. Physiologically, 30 is still 30 and is on the downhill slope of fertility.
Infertility is a woman issue
50% of couples dealing with infertility are dealing with male factor infertility. Here is an informative article about male factor infertility.
Working out keeps you from getting pregnant
If you're an Olympian or some other kind of crazy intense athlete then the round the clock workouts and low body fat will probably hurt the process. BUT, exercise is imperative for your overall health and thereby, healthy reproduction. Even someone who works out harder or more often than the average person still isn't going to negatively affect their chances. Also, if you do get pregnant, a stronger body has a much easier time of it and a healthier overall pregnancy.