Back from my midwife appointment. Bump is measuring fine now (although I got the impression that she kept running her hand down the measuring tape until she got the measurement she wanted).
With regards to my bad back, she said that if it's bad then source private help (i.e. a chiropractor or osteo) because by the time they could get me an appointment with an NHS Physio I would probably have a 1 month old baby and my problems would be gone. Although it is upper back, she said it would be because my pelvis is changing shape to accomodate baby, and that will affect my whole torso.
Baby's head is one fifth engaged
... I am pretty sure that he/she can still become un-engaged again, but it is still nice to hear.
I decided to ask her about strep b, and she said that the reason why the NHS don't test for it is because about 1/3rd of expectant Mum's would come up positive, and so would be given antibiotics at the birth, and for the vast majority of those women it would be a case of giving them drugs that they do not need as the baby is highly unlikely to react to the strep b anyway.
She also said that I may screen as negative this week, yet be positive for it next week.
Basically she tried to put me off taking the test privately, but I am still thinking I might (but will now leave it until 38 weeks or so to do).