I'm glad you did your research!
If the dry skin is related to subluxation, it is likely to be cervical. However, all the nerves are connected in some way, and it is not uncommon to have a sacral problem being causing headaches, for example, or an upper cervical issue causing constipation.
Yes, please get yourself looked at! An MVA, even at very low speeds, can cause a lot of trauma to the spine and spinal cord, and many MVA victims have subluxations of the pelvis which most certainly can cause problems for a baby living inside, and can even result in your baby being subluxated even before being born, not just during the birth process. If your other child hasn't been checked after a birth like that, it would be a good idea to correct any problems right away.
If you have a chiropractor you trust, great. If you need referrals, let me know! Have a great day, sweetie.