Hi. Yes I absolutely thought the same as you and was getting extremely stressed. We are told at school it's super easy to get pregnant, you can get pregnant any day of the month, and spend a lot of our lives trying to avoid getting pregnant, then when you want to try it's tricky.
Initially, my husband and I were having unprotected sex for about 4 months but we weren't doing it every day and I certainly wasn't checking the calendar so I shouldn't have expected to get pregnant - and I didn't. We were of the mind set "if it happens, then great".
I am 33, he is 37 and we are ever so slightly overweight (according to BMI). We don't look overweight to look at (in my opinion) but the calculators say we slightly are.
In January this year we decided to properly start trying. I cut out alcohol almost completely (maybe 1 drink a week if that) and he cut down too (maybe 2-3 a week). Some people say that cutting out alcohol is a myth - they might be right, but I just didn't want to think "what if" if I didn't stop. We both started exercising more, and took Wellman/Wellwoman supplements to help conception (again, some people say it's a con, but we had nothing to lose). I used Clearblue ovulation sticks, which I highly recommend. It tells you exactly when to do it. It was very boring to be honest, and we only had sex when there was a chance it worked.
January and February were a bit of a disaster as we were both ill on my "peak days" so we couldn't do it, so it minimised our chances. We tried properly in March, April, May and June and conceived in the June. In the June we used the "Sperm Meets Egg" method too (including sticks) and it worked. Not sure if it would have worked anyway, or if it was the SME.
I would recommend the sticks - about £20 a month, but if you are the sort of couple who can't or don't do it every night for whatever reason they're very useful.
I spoke to some GP friends of mine and they said that on the whole / generally speaking, if you don't think there is reason why you can't conceive (eg you are not aware of anything health wise) the high chances are you'll be able to conceive within a year and the main reason couples struggle is because they are doing it on the wrong day.
Good luck, and don't worry if it doesn't happen this month.