Yes you can get pregnant right after.
If you're not pregnant, then no. It is not a miscarriage. Your period is just screwing up.
No. Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving, generally defined in humans at prior to 20 weeks of gestation, or about 5 month pregnant.
No. It can take 8 or more weeks to get your period back after a miscarriage.
You can get pregnant NOW, it is not still from the miscarriage. If you feel like it, go for it.
A heavy painful period with clots.
4 weeks pregnant is when your period is due, this may be a period or if it is really heavy and you have had a positive test I am afraid you are probably having a miscarriage.
There are 13 weeks in a 3-month period. You are 3 months and 3 weeks pregnant.
It may depend on the reason for the miscarriage and how far into the pregnancy she was. There is no reason not to start trying again right away, after a very early miscarriage - with your doctor's OK.
Yes
Yes
Normal bleed after a miscarriage is 1-2 weeks so it's not your period. You get your period back sometimes within 8 weeks from the miscarriage.
No. Go and see a doctor. You are probably having a miscarriage.