YABU
Why would you be concerned? The cover will be being provided by consultants and associate specialists (senior Dr's who are not consultants and not in trainee posts). The midwifery staffing and theatre staffing (should you need it) will be unaffected. The trusts have had quite a long time to plan it all. It is only elective care which will be severely hit, as consultants will be covering emergency care and so cannot do their routine work.
In the event that the hospital feels the situation is unsafe and consultants overwhelmed, the juniors can be called back in.
It seems you are one of those who has been fooled by the government's shameful (and dangerous) rhetoric.
I will reiterate for everyone pregnant- if you need emergency care whether it be because you are in labour, reduced feral movements, bleeding or whatever- then please contact your maternity unit in the usual way. You will be seen. You and your baby will receive the care you need. Please don't be frightened or worried, please don't be put off from seeking help because of the government's scare-mongering.
Same goes for everyone who is unwell- your GP will be open, A&E will be open and staffed by senior clinicians. Same goes for medical and surgical admission units, and the wards. If you need emergency care, you will get it. If you are in hospital already, the consultants are covering the wards in place of the junior staff.