Yes.
Yes
Yes
Yes.
Yes.
Yes
yes,miscarriage is a great risk of a 3 week pregnant woman.
No. It can take 8 or more weeks to get your period back after a miscarriage.
No they can not.
If the doctor examined you after the miscarriage you are not pregnant anymore. He would've caught it. It takes several weeks for the hormones to settle so that might be it or you are pregnant again.
Ive heard once there is a heartbeat the chances of miscarraige go way down.
Possible if you took no protection and were ovulating.