Vegasil is an application to get relief from non-specific itching. However, you have got a lesion on the labia majora
. From your description it appears to be ring worm
. You have to get the lesion diagnosed and treated. If are 38 weeks pregnant, meaning there by that your delivery is just round the corner. If such infection is left untreated, it may contact the baby during birth. Please report to your Obstetrician or Skin specialist and get diagnosed and treated completely. Both these conditions can be treated by local application of medicines. Whitfield ointment can cure ring worms while permethrin cream can take care of scabies. Any other lesion will be diagnosed by viewing the lesion by your doctor.
Ingrowing hair will cause more of pain rather than itching.
I hope you are well convinced.
Dr. Nishikant Shrotri