I had really awful pelvic pain in my second pregnancy when I was doing a lot of walking and carrying my toddler. I found lots of gentle yoga really made a difference, and being careful about how I sat/got up - keeping legs together. Because the relaxin makes all your ligaments etc loose it means your pelvis is not as well supported! I have a support band as well that I wear if I know I'm going to be on my feet a lot!
I did actually find it got better for a bit, I can't remember exactly when but I think maybe from between 24-28 weeksish, because the baby actually gets bigger and lifts out of your pelvis so there's less pressure then (for a bit anyway until the end!)
I have been lucky this time apart from after one day when I definitely did far, far too much walking pushing a pram!
I've been sent a random growth scan appt for 28 weeks so that's only 4 weeks away, but I think I'll try and reschedule as time is not great with work/childcare pick ups. My trust does routine positional scan at 36 weeks too, so get to see baby a couple more times, although I am wary as I don't want them to start scaremongering about my 'big' baby!
My eldest has been talking to the baby on the 'tummy telephone' and it is so impossibly cute. If anyone has any older children, we have quite a few books about new babies but just got give 'There's going to be a baby' by Helen Oxenbury and it is really super sweet, recommend! both the boys keep requesting we read it. xx