Hai sayang, bengkak area tu memang normal during pregnancy sebab hormones dan blood flow bertambah, especially kalau pakai tight underwear or your body's just adjusting to the extra weight, a few of my mum friends experienced the same thing around this stage dan it went away after delivery. Tapi since you're 26 weeks, best to mention it to your doctor or midwife during your next checkup just to rule out anything else, especially kalau ada redness or discharge, okay? Try wearing breathable cotton underwear for now dan see how it goes, most of the time it's totally normal and nothing to worry about, but it's always better safe than sorry with pregnancy changes!