First 8-9 months is not that long. Second, its hard because there are a number of conditions that have to be met for conception. Issues of timing, penetration, sperm motility etc. all play a part in the sperm finding and fertilizing an egg.
I would not get up and go to the loo immediately after sex. Lie in bed with your hips raised for at least 15 minutes. If, after a year of trying, you still haven't conceived, then you both need to see a doctor.