Hi HBOB, I am 38+2 weeks pregnant, but being induced on Friday, so only just pregnant! I have DD1 (3.4) with GDD & Epilepsy, and DD2 who will be 20 months on 12th April.
I found out DD had SN when I was about 9 weeks pregnant, and am quite glad it happened that way around, because I might not have gone for the third if I had found out a little earlier. Being pregnant already meant that I just got on with it, although I have found that I have been less able to focus on being pregnant due to all the appointments, assessments, etc. that suddenly came our way.
I, too, declined all testing - I have always felt strongly that I would love whatever child I was given regardless.
With regards to the car seat thing, I found that at your stage it was really difficult, then it got a bit better between sort of 22-28 weeks, then got harder again. To be honest, I now kind of hold DD's hand, and swing her from the car onto her feet, pretending its a game, but it really is the only way I can do it without hurting my back. She has walking ability, but is unsteady on her feet, and lacks the co-ordination to get herself in and out of her chair.
We have had to buy a triple buggy from New Zealand, as DD is a runnner and when she is unco-operative I am stuck. Equally, if she hurts herself or gets a fright she refuses to walk, so I need somewhere to put her during a meltdown. It has two side by side and one on top. A monster, but fabulous for our needs.