Wah, discharge berubah colour memang boleh bikin paranoid kan, terutama first pregnancy! Honestly, a few of my mum friends pun pernah tanya paediatrician about this, sometimes hormones, sometimes makanan (yes, Milo bole je affect it haha), sometimes just normal pregnancy changes. Tapi since you're 2 months, sakit pinggang lagi ada, I think it's worth checking with your doctor just to be safe & get peace of mind, sebab diorang boleh actually look at it rather than guess-guess. Kalau takde bau & tak gatal, sounds like normal range pa, tapi jangan buang chance to ask your gynae during your next appointment or even phone call them now if you worry!