Does anyone know of a website that can give insite to a pregnancy woman's immune system or if anyone knows the answer to my question that would be fine too:

I have been sick twice already during my pregnancy. I used to have such a great immune system because I would work out like a madwoman at the gym, however being pregnant, I watch how hard I work out and how much now because I want to be careful.

Why all of a sudden does my immune system seem to be lacking all of a sudden? Is it just because of pregnancy or what. I just want to understand what is going on with my body is all.

Thanks for any insite!