Yes, that yellowish sticky drop sounds like colostrum, totally normal at 39 weeks, and actually a good sign your body is preparing for baby! It starts out quite thick and golden, and some mums find only one side produces at first, so no need to worry about that. On the nipple stimulation side, it is a bit of a mixed picture, some mums do find it helps things along, but the general advice seems to be not to overdo the pumping sessions, since there is a difference between gentle stimulation and prolonged pumping that could cause stronger contractions than expected. Since you already have an induction date scheduled and no dilation yet, it might be worth checking with your gynae or midwife first before continuing, just so they can advise how long and how often is safe for your specific situation.