OP I could have written your post! I am pg with dc4, and all if mine have been back-to-back, and I've had SPD with them all too. The last 2 were also very overdue (14 & 16 days) so I can imagine the same happening for me this time...
One sweep managed to bring on labour with %231&2, but I had FIVE sweeps with %233 which didn't work.
Dc1 was born face up (difficult birth
) but dd2 & 3 both turned during labour. I spent a lot of time on all fours. I remember clearly feeling dc2 turn and drop down and engage while I was in labour with him, it scared the life out of me (literally felt a 'thud'), but I went on to have the most wonderful, positive birth experience.
With dc3 my cervix was also not ready, even at 14 days overdue (have you been given a Bishops Score? en.m.wikipedia.org/wiki/Bishop_score%23section_2
Mine was '1' at 14 days overdue, so I was so fed up thinking that even an induction was going to fail. (and very upset that my home water-birth was going out of the window).
I opted to go past 14 days overdue with daily monitoring. They scanned me at 15 days over to check if the fluid levels had depleted (can happen when overdue and is dangerous) and discovered that my fluid levels were three times MORE than they were supposed to be (no wonder I suddenly got huge
) so I had to be immediately induced.
I had to go through all of the staged of induction - pessary overnight (I really didn't like this, placing it was difficult with my awkward cervix,and it felt like I'd been kicked in the fanjo), then I had my waters broken (this was fine - although GALLONS of water!), and finally as nothing had started by this point - the drip.
I was so scared of that drip. Was so upset when they attached it. It brought on contractions and dd was born 4 hours later. In comparison to my non-induced births, yes the contractions were definitely
more intense, but I would say it was only the last 10 minutes before she was born that I felt I couldn't cope with (I had gone from 7 to 10cm in that time). But I managed with G&A and breathing (did hypnobirthing) and didn't have an epidural.
Looking back it was actually fine, so much better than I had feared.
Make sure you get on all fours as much as possible before and during labour, also draping over a birthing ball is good and is also lovely relief for the SPD.
Good luck OP, let us know how you get on!