Hcg levels

So I found out last week (Thursday) I was pregnant and my doctor told me to come in for blood work to confirm. They confirmed it (due October) but said my levels were low (14). She said not to worry though bc I'm just super early! (I was three weeks last week) My doc told me to go back for more bloodwork Tuesday (tomorrow) to see how well my hcg levels are rising. Has anyone had levels that low and had their levels rise good? And have a happy healthy pregnancy? Any advice would be great. Im completely nervous over here. Im sweating bullets waiting for tomorrow morning to come.