Hi there a.
I read your problem with interest & empathise with you & note that you are a virgin.
Your problem appears linked to your periods or menstual cycle & note that the rash
develops in & around that time.
So to answer your question, yes, it is very likely that sanitary pad usage by virtue of the material & /or mechanical friction or leaving it behind for long duration is the guilty party here.
Might i suggest you try the use of tampons but consult your gynec first & dont forget to take them out & leave them on overnight for long hours as this may lead to serious complications.
Locally use a cream containing hydrocortisone-fusidic acid
combination & this should sort you out.
Dr Praveen Rodrigues MD