You have not yet understood the beauty and elegance of free movement.
Firstly there is no EU 'visa'. Drop that visa mindset.
Secondly, if hubby has been a qualified person since you first arrived in UK in 2013 then you have been his EU family dependent in UK since then.
(OK you happened to have a Tier 2 domestic visa too - that's fine).
Absence from UK due to childbirth and pregnancy are valid reasons for a one-off absence (and escape from our climate) for up to 12 months. Your sojourn falls within that.
If hubby is to be a stay-at-home dad on return to UK simply put CSI in place (for all) so that he assures his selfsufficient qualified person.
That keeps your PR clock running (both of you) - since 2013.
So it won't be starting from zero early next year
With qualifying period starting in 2013 (remember, not 2017!!) you may acquire the holy grail of PR status by 2018.
And despite all wild talk of
Brexit UK is still likely to be in EU even as late as 2019.
So you have probably smashed it.
Takeaway
Confirm if sponsor was indeed a qp since 2013.
Get CSI.