ds1 was an (unplanned) unassisted homebirth (homebirth bit was planned) after a quick labour with ds1 (2hrs).
ds2 basically went like this.
- waters: hmm, can't be, 3 weeks early (as was ds1)
- 10 mins later 1st contraction: shit is it, better tell dh & call hospital
- 15 mins later (max): better just check nothing happening - reach down and deliver ds2 head into my hand.
The community midwife said afterwards that if something had been wrong then it wouldn't be a quick delivery - something going wrong is almost always a failure to progress, by which time help would have got there.
My dh was there, but I fully expected him not to be as at the time he was away from home Mon 6am - Fri 9pm (I had ds2 late Fri night).
My plan for this was to ensure the front door was unlocked at the first sign of anything happening.
If you are worried about giving birth alone then talk to your midwife, but if it does happen then it is almost certainly because it is very straightforward, and someone will be alone shortly after.
My dh called 999 after I gave birth, which I didn't really see the point of as everything was fine and midwife was called out. They took about 15 mins, and just had a very quick look at me and the baby (didn't actually touch either of us) and then just stayed until the midwife turned up (and then until I delivered the placenta in case we needed to be transferred to hospital).
Agree on keeping a phone on hand.
My friend also had an unassisted homebirth (with her 3rd, 5 months after mine). Her's was somewhat longer but her DH called 999 while she was in labour and they stayed on the line and talked him through everything.