I track my cycles on this site and on mymonthlycycle.com b/c it gives just a little bit more detail.
But I agree with kiwi....the most important thing is your health and your baby's. You need insurance and health care and if that's not a priority then maybe babies should wait. Not sure of your situation but in my situation....deciding on whether to start TTC with my husband took a lot of consideration.
If can't afford insurance, how will you afford a baby?
i have done that my last period was aug. 18th for 4 days. before that my period was june 12th for 5 days and the one before that was feb. 10th for 5 days.. i kno i need insurance but its hard when i cant really afford it right now
Use a calendar and whenever your period starts, put a red circle in one of the corners. For every day you bleed, mark it with a small red circle on your calendar. Do this for three months and see if there is any consistency. You can also use online calendars to chart your cycles.
I used to have 2-day periods and that's actually fine and even normal. So it isn't the length of the period (unless it becomes excessive, as in 2 weeks of non-stop bleeding).
And finally I would suggest getting health insurance if you are able because if you do become pregnant you'll need healthcare.