I just had my first OB appointment today, and am very lucky to have a (so far) healthy little bean on board. However, he told me that I should keep my heart rate below 150 BPM when exercising. I just went on a run today with an HRM, tried to go slow, and saw that my average heart rate was 177. I also did a 15K this past weekend, didn't wear an HRM, and know for a fact that I was pushing. Oops . I'm trying not to panic, but want to know what other runners' experiences with running have been while pregnant? Am I harming my baby by being over that 150 BPM mark? I am by no means a fast/furious runner (pre-pregnancy my fastest miles were 8:40 or so), but I've lowered the intensity since finding out about the baby. I want to strike the balance between healthy and safe, and since this is my first, I'm pretty clueless. Thanks to anyone who wants to share her experience!