I agree with the others. My cycle is around 23 days and my luteal phase is 10 days, so my doctor has always told me that I'm OK since my luteal phase is sufficient. During one of my cycles, I had my progesterone checked and it was good, so that was a big relief. I think it would be a great idea for you to figure out your luteal to make sure it's at least 10 days or so. It might also be good for you to get bloodwork and have your progesterone checked. This should be done 7dpo. Good luck! :)
It all depends on how long your luteal phase is. I have a 24 day cycle and a 10 or 11 day luteal phase (time from ovulation to your period) Since it usually takes between 6 - 12 days for the egg to implant it would be nice if my luteal phase was longer but we still have good odds and pregnancy is achievable. However if your luteal phase is less then 10 days that is when you need to look into it. Often it can be low progesterone etc. which can be easily treated. If you are not used to charting you could try and use an ovulation predictor kit to "pinpoint" ovulation as best you can and then see how many days after that you get your period. That would be the place to start. If you have a 26 day cycle but a normal luteal phase and good cervical mucus prior to ovulation you should have nothing to worry about. Good luck!
Don't know if it's any harder or not, but I had a 25 day cycle when we got pregnant...but we did have to use Follistim to help my ovaries along a bit the first time and progesterone during the first trimester (of both pregnancies). Second time was natural, still running 24/25 day cycles (during breastfeeding even).
Best of luck and don't give up...but get tested if you feel something is just not working like it should.