Hi.
I often say that sexual fantasies are our own private playgrounds, where we can do what we want. So, I would never say that your fantasies are abnormal.
Sometimes fantasies can be a way of alerting people to things they truly do want to explore, while at other times people fantasize about things they would never act on in real life. It may be hard to tell what your fantasies mean at this point.
Even if you do find that you're interested in pursuing women, that doesn't necessarily mean that you won't be attracted to men. (I noticed that you didn't say that you weren't interested in being intimate with your boyfriend or guys, in general.) You may, in the end, find that you are bisexual.
Give yourself a little more time to observe your feelings and attractions in order figure out what your fantasies about women mean and to which gender or genders you're truly attracted.
In the meantime, you might want to check out the "confused and curious" folder on the "when girls like girls" board. There are lots of other gURLs on that board who can give you advice and additional support.
Take care.