Your cycle length of 26 days means you're ovulating around day 12 to 14, about two weeks before your next period. Your fertile window is the 5 to 6 days leading up to and including ovulation, so that's when intercourse is most likely to result in conception.
Next Steps
Track your cycle with an app or ovulation kits to pinpoint these fertile days, and aim for intercourse every 1 to 2 days through that window. Start a folic acid supplement now, since it works best started before conception. Reaching a healthy weight before you start trying also improves your chances and makes a pregnancy easier to manage.
Health Tips
If a year of regular trying doesn't lead to pregnancy, it's worth a preconception checkup sooner. Please see a gynaecologist to confirm your cycle and weight aren't affecting things before you begin.