I dont know my cycle :(?

Check out this link: http://www.ccli.org/ It is actually for couples who want to do natural family planning. With NFP you learn to take your temperature every morning, the temp rises when you are ovulating. Also, it teaches you how to read the mucus signs which is really pretty easy, but it's helpful stuff to become familier with. So, it is a great way not only to avoid pregnancy but also to acheive pregnancy. Definitely recommend it!

Okay, here is what you do. You're cycle starts on the first day of your period. So when you get your period this month, write it down. Then no matter how long your period is this month, my advise is to get a home ovulation test kit. Start taking the tests on the 10th day of your cycle. This would be 10 days after you start bleeding. Take the tests until you get a positive. This is important because this determins when you are most fertile. When you get a positive, that is when you are ovulating. This also comes in handy if you are not ovulating (which can happen) because you can tell your DR and they can start tests to see if you can even have a baby. In my opinion if you have been trying for three years, something is up. You really need to keep your DR in the loop on everything.

It doesn't matter how many days long your period is (except, perhaps, if it is only one day of spotting and not a true period). You need to keep track of what day your period starts on and how many days are between the first day of your period and the first day of your next period. If you can re-post with the dates your period started on each of those months, we can maybe help you out a little more.

I'd get a little calender notebook of some sort, and for the next few months track down when you get your period each month. You ovulate starting about 15 days prior to your period, which is the best time to conceive. If your period comes in or around the same time frame each month, it shouldn't be to difficult to find out when you're ovulating. Hope that helps! Good luck :)