Don't quit riding now because if she does get pregnant you won't be riding significantly the first few months after the baby is born. For me it was probably 6+ months before I had the opportunity to really start riding again after my daughter was born, though my wife had a C-section and needed quite a bit of help initially. A lot of it also had to do with sleep deprivation. lol

Also don't stress the whole "process." It's amazing how something as fun as sex can become a chore when there is pressure added to the equation. I know when you're trying to make something happen and when she's planning the dates for boogey-nights, it can become monotonous. As long as there is nothing seriously wrong, it'll happen.