I've never had bad skin, even in high school, but my first trimester was awful. I even had a pimple on my LIP! I didn't even know this was possible. Late in my first trimester my usual skin seemed to return--especially after I replaced some of my makeup.
This is slightly off topic, but I thought some might appreciate the information: The reason I've thrown out pretty much all the makeup I own over the course of the past few weeks is because I read the labels. There was all kinds of toxic stuff in it known to cause cancers, thyroid problems and reproductive issues -- even the high-end stuff I owned. I replaced everything but a few items after doing some research.
The following nonprofit organization provides a database that will tell you the levels of toxicity and potential threats in your products--and gives each a health rating: http://www.ewg.org/skindeep/ You just type in the names of your products. (If not listed, you can also type in the ingredients to find out the perceived potential problems or lack of problems.) Hope this is useful to someone else.