I had a blood clot and a small baby this pregnancy too. I had two very severe bleeds and 10 weeks of spotting. At one point the clot was much larger than the baby, who was measuring 5-6 days behind. But the clot began to dissolve around 14-15 weeks, and the baby started catching up around then too.
Subchorionic hematomas (the fancy name for the kind of blood clots you and I have) are actually not uncommon, and in about 95% of cases they do not cause problems and dissolve on their own by 20 weeks.
I created this thread on the High Risk board with SCH resources:
http://www.justmommies.com/forums/f1...rmalities.html (Placental Abnormalities).
You should come visit the High Risk board, there are a lot of us there who are having the same kind of problems.