I'm only 7 weeks pregnant and when I walk a short distance, my heart rate shoots really high. Resting HR is around 65-70ish. When I walk about 30 yards, I feel my heart beating out of my chest. My heart rate shoots to 130.... by just walking.... Note: I exercise daily 60+ mins cardio and resistance training. I have never had this problem because I am very fit and healthy. Could this be a sign of pregnancy? Like I said, I'm only 7 weeks so I don't know if fatigue has something to do with since I've been extremely tired. What could I be?