Scared of Miscarriage!

I'm 6w5d pregnant and I'm so scared of miscarriage because I've had 2 really early clinical miscarriages before.  I had my first scan today because I have been having really bad cramps. My baby's heart rate is 125bpm and the doctor said everything looks great. It was so beautiful to see my little baby's heart beat. However I've been so tired and have been feeling terrible to the point I struggle to get out of bed and I have no energy what so ever. I feel so useless curled up in bed.