I have oc this pregnancy and last and the main sign can be itchiness. It's not always in certain areas as personally my itching has always been all over rather than localised. The itching is normally quite extreme though. There are other symptoms including pain directly under the ribcage, jaundice, dark urine even after drinking plenty and feeling generally unwell but sometimes there are no other symptoms what so ever. It's definitely worth mentioning it to your midwife, a simple blood test can check whether oc is the cause but other that that it really can just be one of those annoying pregnancy things. I wouldn't risk leaving it unchecked though, it can be dangerous if left untreated.