A long-standing patch like this, present since 2017, often has quiet spells and flares, and early pregnancy hormones can be one trigger for a flare. Self-treating it now, even with a non-medicine option, isn't the safest move until you know it's fine in pregnancy.
Next Steps
A dermatologist visit is the right next step. Tell them you're
pregnant so the plan they give you is adjusted for that, and let your obstetrician know about this too so your care stays coordinated.
Health Tips
Please don't start any new remedy, herbal or otherwise, without confirming it's safe in pregnancy. See a doctor sooner if you notice more redness, oozing or pain in the area.