You should contact your midwife or antenatal clinic to inform them that you are currently in self-isolation for possible/confirmed coronavirus and request advice on attending routine antenatal appointments.
It is likely that routine antenatal appointments will be delayed until isolation ends. If your midwife or doctor advises that your appointment cannot wait, the necessary arrangements will be made for you to be seen. For example, you may be asked to attend at a different time, or in a different clinic, to protect other patients.