I asked an OB about creams, etc. while pregnant (I had specific questions about a few things I had applied to my skin). She said that unless you're using something with retinol in it -- which you really should avoid -- it's REALLY hard to affect the baby using something topical.
I know several very fair women who've used sunscreen extensively during their pregnancies without any problems, and I use a moisturizer with sunscreen in it every day. Here is an article that might help put your mind at ease: http://www.pregnancytoday.com/articles/healthy-safe-pregn...
I know particularly in the beginning of a pregnancy, you worry about every single little thing you could be exposed to. As it progresses, however (and the number of things you're exposed to increases) you start to realize that we live in a very chemically world and you're exposed to these things probably every day. Our bodies are amazing, however, and protect our babies from nearly everything! It's a good idea to minimize exposure to toxins where you KNOW they are, of course, but if you use common sense, your baby should be just fine!