I'm sorry to be the one voice speaking differently, but, from what I have seen, yes, there can be pretty noticeable effects from being a woman in mostly-male-dominated technology companies.
This has nothing to do with being a woman intrinsically; women can obviously be just as good programmers as men (don't forget that the person generally considered the first programmer was Ada Lovelace, the inventor of the first compiler was Grace Hopper, and women have continued to make major contributions to the field ever since!). Unfortunately, that effect that you have mentioned, being sometimes talked down do, does continue in a lot of places, along with other difficulties.
There are a variety of systems coming into place to try and give support to women who are programmers. Two that I have heard spoken of highly are Systers (http://systers.org/mailman/listinfo/systers) and the Women in Technology chat group (http://witchat.github.io/). They can help you feel less isolated, if that happens, and offer suggestions if you need them for particular approaches.
Please do not take any of this to mean that you don't belong. You absolutely do. The fact that you chose to study computer science alone proves that!
If you have questions I can try to expand more, but since I am only getting this through (frequent) hearsay, I know that my answers will be limited.