I have had the itchiness since early second tri. I thought it was thrush so did the yoghurt thing and tried canesten but they didnt work. I also get this in the few days leading up to my period too so I am putting it down to the hormones. Not much to do about it unfortunately. Maybe make sure you are rinsing the detergent out of your washing properly so knickers dont irritate it any extra and make sure you use colour/fragrance free loo paper too also sleep without pants! TRY not to itch cause it does make it worse.