Toenail fungal infection is a resistant problem. Antifungals potent enough to help should be avoided in pregnancy. There is a safe means of getting rid of the problem but you need patience. Soak your feet nightly in a solution of 2 quarts of warm water and half a cup of ordinary clorox. After 6 months, when the new nail growth is complete, the problem will be gone. Seems a long time, but it works.
Yes, OTC anitfungals. Vicks might work on nails but is not a good treatment for other fungal infections, especially if it is in the genital area-ouch! Several over-the-counter (otc) preparations are available. Just follow the directions on the package. Some preparations are for symptom relief only but the infection will continue. If not sure what the rash is, or if it doesn't improve, see your doctor.