You really can't put too much weight into one beta number. As long as that number is doubling like it should than it doesn't matter what you first reading is. As long as it is over 25 I wouldn't worry yet. It could have been a late implantation. I have seen smaller numbers than that end up in pregnancy. Hang in there mama. Let us know what your next beta is.
4/26/12 at 6:54pm