Your HCG level is perfect for your gestation.
I didn't have any stmptoms but tingling boobs from 6weeks with my 1st pregnancy. Other then baby kicks from 19weeks and extreme weigh gain I had no symptoms at all I was pregnant ever.
With no2 I got morning sickness from 15weeks till over 30weeks. I never had nausea etc until the 15th week. Other then the obvious (kicks, weight gain etc) some women don't have any symptoms of been pregnant.
As for the stretching that is normal in early pregnancy.
Have you booked for a scan or more blood tests just for peace of mind?
Congratulations too by the way.