Hmm. Well, if it were me, I'd loosen the pants, and also chart when it happens. Is it right after your period, for example? Then mention it at your next ob/gyn exam with all the data. If it happens in relation to your period, I would wonder if it's BV.
When it happens, especially if it's happening at a time when you won't have access to a doctor for a while to ask, try a sitzbath in a solution of epsom salts, or a weak solution of white vinegar in water. Do it every night for a few nights, and see if that helps.
Hi, I've heard that clitoris changes during persons lifetime but idrk... I have the same problem, I think it's because of masterbation...