I can give you another success story, I'm 36 and am 9+5 pregnant with my first after trying for 14 months. After about 8 months I went to my gp and lied and said we'd been trying for a year, so I had all the usual tests, bloods, hormones, pcos scan etc etc, and everything came up normal. We were doing all the right things, bd'ing every other day throughout my cycle, legs up afterwards, taking folic acid and still nothing.
I was referred in Sept 06 to the assisted conception unit at my local hospital, and started the same battery of tests again (why? Cos the NHS don't 'arf like spending money!) again, nothing wrong. I also had an hsg, which was really painful. I was convinced that meant I had a blocked tube, but when I finally screwed up the courage to ask my gp for the results, turns out my tubes were fine, just never been stretched like that before, so that's why it hurt!
The consultant at the hospital told my dh to start taking something called Wellman, a vitamin supplement to boost his sperm. The numbers weren't down, but the numbers of deformed ones was a little too high.
I too was a little obssessed about getting pregnant, insisting on dragging poor old dh to bed regardless of how in the mood we were, and lots of people told me to relax and not worry about it and it'll happen. Over Christmas, taking advantage of a few days off, dh bd'd every day for five days (contrary to advice) 2 days before ov, on the day of ov, and 2 days after just to be sure. On Jan 14 I got a bfp!!
I don't know if it was the hsg clearing out my tubes a bit, the Wellman vits dh was taking, or bd'ing every day that one time, or a combination of both, but I'm sure that trying too hard isn't going to stop someone getting pregnant, unless you're working yourself into such a state that you're actually threatening your own health. You'd have to be really stressed about it to affect your chances of having a baby, and I'm sure that that level of stress would have some kind of physiological indicator a doctor would pick up, like high blood pressure, hormonal disruption, etc etc.
All I can say to Wishing is 8 months isn't that long, so don't sweat it. And if you are worried, don't worry that your worrying will make it difficult to conceive, because you just end up on a downward spiral of worry. And everyone else, keep at it, don't give up the faith, and remember genuine infertility is still pretty rare thank goodness, even Dr Robert Winston admits that most fertility problems people experience these days are down to not enough sex! So get to it, and as I said to dh when we were trying, it's hardly the worst thing you could put yourself through, imagine if we had to poke ourselves in the eye with a sharp stick each time we wanted to get pregnant, now that would be a chore!
Phew what a long 'un! apologies for what may seem a rant, good luck to all those trying!