20 week scan

So got my 20 week scan this week and I am so nervous and anxious about it, I'm scared there won't be a heartbeat, even though had a private scan only 2 weeks ago and all was OK. I had a miscarriage beginning of the year but was an early one and all the way through my pregnancy iv been so anxious. I started feeling babys movements only small ones mind but Saturday I saw and felt a couple and I occasionally do but baby has been quite quiet since I have felt movement but not an awful lot. The early kicks are new to me as with my first I had an anterior placenta so didn't feel the early kicks at all. Sorry to waffle on, I just don't no how to get rid of this anxiety and fear!