Feeling kind of "iffy"...

I'm feeling kind of "iffy" about our chance of conception this month. I usually don't ovulate until at LEAST CD20... So I completely was not expecting it at CD 16. We almost didn't even have sex that day, but I noticed some EWCM (just a teensy weensy bit) that day, so I made sure we did just in case, not expecting it to be an issue. We also had sex 2 days before ovulation, and the day after... But usually we have sex every 24ish hours for a few days leading up to ovulation, the day of ovulation, and the day after... I don't know. I suppose anything is possible. I just wished we had of timed it better...