Hi Gena, I also have short cycles (25 days) and the cycle after I had my first m/c I O'd positively on cd 4. I know for sure cause I ended up pregnant and have a 13 year old son as a result of that early O!

After this last m/c Im pretty sure the same thing happened, cd4. Only I wasnt lucky enough to catch the egg that time. Next cycle Im going to start temping, so dont be surprised when I pop up asking you tons of questions about it, cause I am brand new at figuring out all this stuff! Good luck!