I have a cyst and i'm 4 weeks pregnant my hcg level is 2400 but the doc doesn't see my babe what could b wrong?

Nothing likely: We don't usually see the baby until at least 5 1/2 to 6 1/2 weeks. In addition that cyst is probably your corpus luteum and it supplies the progesterone you need to stay pregnant until your placenta takes over production around 12 weeks.See if your Ob will repeat the hcg as it should continue to rise if this is a normal pregnancy. A repeat US in a couple weeks may be a good idea too.