Running while pregnant?

Hi ladies!

I'm 6 weeks along and I've been receiving some conflicting advice on running / working out.

Pre-pregnancy I ran 6 days a week and also did yoga, HIIT, weight lifting and was generally very active. For reference when I run I average about a 7:20 min mile for at least the first 5 but would often do longer runs and averaged around 40 - 50 miles a week. Also, I run / race hard and really push myself for PR goals frequently.

My (wonderful) ob-gyn told me that running is absolutely fine throughout my pregnancy but warned me that at about month 5 or 6 I would probably naturally slow down due to balance issues. However another ob-gyn I know and respect advised me against running that hard. He said high impact workouts or high BPM workouts could increase my risk of miscarriage - especially in early pregnancy. I'm so confused!

In light of this all I stopped running so hard this week. I switched to biking, swimming when possible and long walks. But to be honest, I desperately miss my daily runs. It's the #1 way I relieve stress and my health and fitness are a top priority for me. I eat very clean and have been active but it's just not the same.

I apologize if this has been addressed in archived posts, I'm hearing such different things and would love the most recent professional advice / thoughts on the topic. What has your doctor advised you? Any insight?

Thank you in advance!