Since your wife is 4 weeks
pregnant, bleeding is usually common it is called as implantation bleed.
And ultrasound report says early intrauterine pregnancy, closed os; so there is nothing much to worry about.
Let’s wait for a week and repeat scan.
Next Steps
Repeat scan after a week. Confirm fetal pole and cardiac activity in further scan.
Health Tips
If bleeding continues, there is sudden gush of blood or if signs of pregnancy like nausea suddenly disappears then do consult a gynaecologist and do not avoid these symptoms. Till then just take good rest, avoid any strenuous physical activity and have good healthy food.
Continue folic acid tablets.