My skin was dry and the mentioned areas like armpits got really dark during first 2 trimesters. During 3rd trimester it changed suddenly to super oily skin, lots of pimples and rough skin. It's all due to hormones and the situation differs from people to people. But no worries, it will all be ok soon after giving birth (not immediately, give it about a month or so after birth for hormones to rebalance back). :)