So I'm running again. I surprised myself last week. I ran 4 miles 4 times over the course of the week. I have noticed that if I settle into a comfortable pace (11 - 12 minute miles with the stroller), then I can run continuously for 4 miles without stopping, except for walking up the really steep sections where the path meets the road when my heart rate just seems uncomfortably high.
I'm still doing prenatal Pilates and yoga, and I also tried an Xtend Barre class that I really enjoyed. I feel like I have a very well balanced workout now, and I'm still able to challenge myself physically without going overboard. I hope that I can keep this up for a while longer through the pregnancy. I know I'll do the Pilates & yoga until I deliver, but I also hope that I can keep up the running or at least keep walking. It will get much more difficult when the heat of the summer sets in.