For the Salonpas, I'd actually hold off for now since it contains salicylates and methyl salicylate, and most doctors do advise caution with those during pregnancy. For a mild sprain, resting it and using a cold pack in the first day or two, then a warm pack after, is usually the safest first step while you wait to check with your PD or gynae. On the TCM side, it really depends on the practitioner since some herbs and acupuncture points are contraindicated in pregnancy, so if you do go, make sure the TCM physician knows you are 20 weeks along. I'd say run both options by your gynae first just to get the green light, since they know your full pregnancy history and can point you to what is safe for you specifically.