I had to give up riding way too soon, I was so short of breath by the time I was 14 weeks I couldn't ride. Took me till 20 weeks to realize maybe I needed my CBC checked (I am an RN). My hemoglobin was only 9.5 (normally around 12-13), so no wonder I couldn't breathe!

Ride as long as you can comfortably ride. Enjoy the pregnancy.