Obviously situations where the mother's life is in danger are kind of a gray area, but I think you could comfortably be "proer"-life and oppose the choice in non-life-threatening situations. Not that I agree, but that opinion wouldn't be "anti-choice".
And most of the pro-life positions people take are also pro-choice, just to a lesser extent than they are pro-life.
Choosing what you perceive to be the lesser of two evils doesn't make you pro-evil; choosing what you perceive to be the greater of two goods doesn't make you anti-{life,choice}.
EDIT: To further clarify, I'm not at all confused as to what camp I'm in. By standard definitions, I'm definitely pro-choice. The point I'm making is that the standard definitions are not hugely useful.
In my simultaneous pro-life and pro-choice belief, I don't believe abortion should be illegal. However, it shouldn't be trivial and easy to do and should require medical oversight and counselling (non-extensive, non-judgmental, and non-coercive). That is to say, any woman should have the right but it must be a considered, reasonable choice (a bit like required for gender reassignment, euthanasia, or any number of significant medical decisions).