Well I am 15 weeks pregnant and back to feeling fairly normal, although still if I do a hard workout I will need the next day off. I can't feel any belly when I am working out but I think I only have a month or so before it starts hindering me.
I ran 10 miles Wednesday, it felt awesome. I just can't explain the feeling of accomplishment that comes with a long endurance run. It gets addicting and you just want that number to go higher each time. The longest I've run was about 17 miles once, and several 13+ mile runs. But being pregnant I am happy with 10 as my upper limit, unless I do a slow half-marathon (it would be cool, but there are no options right now unless some friends organize our own). Besides, I have a 2-hour childcare limit at my gym and I was 5 minutes late! (my actual run was 1 hr 48 mins, but I take a lot of bathroom/stretching breaks!)
Then today was a 10K race. Here are some photos from that. My time was 69 minutes, about 10 minutes slower than I ran it pre-pregnancy. After the race, they did a 1-mile fun run which my son joined me for. The winners are based on accuracy of predictions, and the runners can't wear watches. So it was actually pretty fun to predict your pace and adjust it for certain paranoias... I ended up 20 seconds off my prediction and got 2nd place.