Congratulations for pregnancy dear pimples ,dark spots nd dullness r due to hormonal changes .so don't worry after delivery ur skin tone ll be normal. Don't use any cosmetic. ..its happens to some women's. I also face same in 1 pregnancy too and I apply fresh aloevers gel twice a day ,avoid oily spicy junk food, take plenty of liquids nd water, take steam too ..u can try these also . U ll get relief too .take care .