Under standard teacher pay & conditions, only 3 weeks notice is required, overriding the statutory eight weeks. Strange but true.
Most teachers returning to the classroom in September actually opt to return on the first day of the school holidays (so as to get full pay over the summer), in which case now is too late.
Legally - totally entitled to change return date from Sept to Nov at this point. However you can see why the school might be rather annoyed - if your relationship with management is not good, this might not help.
There's more justification if you've only just been told of things that affect your decision (eg if you've just been told that your reception-age-child will be doing half-days in September, having expected full-time).
Not so bad if you know that they'll be able to cover you - more likely in primary. The same person who covered you this term might be able to continue, and supply teachers tend to be short of work for September, so in primary and some secondary subjects there might be little difficulty.
You do have two days a week to help settle your children ino their school/nursery.
Asking "if it would be possible" doesn't make a lot of sense; if you give notice to do so, they can't stop you, so it is definitely possible. A better question might be "if I delay my return, what will happen to my class(es) - would the maternity cover teacher be able to stay on?"