i too don't have much luck tracking mine, they appear to be 3 weeks apart light and full of pms up to 2 weeks before due i only get one good week symptom free a month i'm sure this is not normal but then what is????
anyhow sperm can live upto 7 days and i have come across this website which does all the tracking for you once you type in the dates its free i'm giving it ago it most certainly can't do any harm. good luck!
www.mymonthlycycles.com
I am also confused by my own cycle in the 3 months since my m/c...It looks like yours went more to the short end whereas mine is almost 5 weeks apart. I wish you the best of luck and lots of baby dust!!
It's always difficult to know when you O. Partly because a m/c can throw your cycle off wack and partly because sometimes stress can cause you to O late. There are 3 primary methods you can use to track - OPK's, charting CM and charting BBT. If you do BBT, it will only tell you AFTER you have O'd, but is useful when you are looking at history. Like Dani said, if all conditions are right, sperm can live for 5 days, but it's usually more like 2-3. This is mostly what I've learned from reading Taking Charge of Your Fertility. I hope that helps. I know how stressful it can be when our schedules/DH/bodies can't all get on the same page!!
Sperm can live up to 5 days. I also know that after a m/c it can take a little while for your body to get back to normal. I am sorry that I can't help you with the rest of your question since I can't even figure my own cycle out anymore even though it is fairly regular! I am sure someone else can help you more with that. I wish you the best of luck!