My feeling is that there's no reason for the crude remarks. However, if you are going to make yourself attractive, you definitely have to be prepared for the attention.
I'm fairly conservative in my dress, but I still sometimes like to make myself up even just to boost my own ego for a bit.
By the way, Lise, one of the most gorgeous pictures ever of me was taken when I was 7 months pregnant. It was Christmas and I'd done my hair and makeup, was in a red dress and we were over at my parents' house. I had only just then decided that my boyfriend and I were going to keep the baby, so the house was celebrating. I look back on that photo and just shake my head remembering how self concious and unhappy being pregnant I was.
When you're pregnant, your skin and hair are in the best shape they will be.
Enjoy it