Not feeling to excited today.

I guess I am in a super pessimistic mood today but I just keep thinking that there is something wrong with this pregnancy. Because I keep seeing other women who have the same due date I do who Ovulated on the same day, but their beta levels were in the 50's the first day and 100's the second. Mine were 12, 45, and 91. Yes they doubled but I'm just so worried that the fact they are so low means something bad.