Hcg madness!! Anyone else with low levels?

HCG is becoming a four letter word! When I first learned I was pregnant- I saw my doc and they drew labs. HCG came back at 79 at 4 weeks 3 days. That was a week ago- at which time they said everything was "normal". I got a call today asking me to go back to redraw??? I read a bunch of stuff online about HCG levels being low, and now I'm freaked out. Rule number one- don't google search medical questions... But I couldn't help myself! Anyone with low numbers and continued with a viable pregnancy?? Also, I know the initial number isn't as important as it doubling over 48 hours... But I just want to know if anyone else started off with low levels and did ok??!!