Well, I got pregnant with DS just shy of 36. When you get older you don't ovulate as regularly, which can make getting pregnant more difficult.
Some advice:
1. If you haven't seen your doc for a pre-natal check to make sure you are up to pregnancy, I would do so.
2. We went the route of every 2-3 days to make sure there were sperm waiting for the egg rather than going through the stress of charting temps or using an ovulation kit. of course we also took the stance if it happens great, if not it wasn't meant to be, so that further reduced my stress. Though you may want use an ovulation kit if you are stressing over whether or not you are ovulating. Remember, once you ovulate, if you haven't had sex in a few days it's too late. The egg only lasts about 12 hours from ovulation and it takes longer than that for sperm to get there. It's best to have sex 1-3 days before ovulation - thus the every 2-3 days method.
3. Once over 35 it's recommended to see a doc about fertility issues for you both once you've been trying for 6 months
it took us 4 months from the time I went off the pill until we conceived, so even using every couple of days (not every day because you need to give his sperm time to build back up), it didn't happen right away.
So please, don't freak out. Doing so will only reduce the chances of success. I know relaxing is hard, but maybe yoga or pilates can help you with that. Best of luck.