Thanks for your query,
In cases where the woman has a failed abortion
and then continues the pregnancy
to term, the exposure to misoprostol
could potentially result in birth defects in the child. It was better to tell your OBG because atleast a anomaly scan could have been done around 18 weeks. You are already 6 months pregnant so nothing much can be done at this moment.
Best of luck and take care..
Hope it helps..