Uy, sa singit na dark at itchy yan, I'd really suggest checking with your OB or dermatologist muna kasi pwede itong maraming possible causes, yeast infection, irritation from products, or even hormonal changes, lalo na if you're pregnant or postpartum. A few of my mum friends din nag-struggle sa ganyan and lahat sila nag-improve once na-diagnose properly ng doctor at nabigyan ng tamang treatment, so definitely worth the clinic visit para ma-rule out kung ano talaga!