i have searched for Rh factor because with this being my last pregnancy and my fiance's first child, i was concerned. but then i found out that the +/- with your blood is what the Rh factor is. Myself i have A+ blood which means i have type A blood with a + Rh factor. Here are the links i found.....
http://www.infoplease.com/ipa/A0877658.html
http://medicguide.blogspot.com/2007/07/can-a-mother-and-b-father-can-make-ab.html
http://kidshealth.org/parent/pregnancy_newborn/pregnancy/rh.html
http://www.biology.arizona.edu/human_bio/problem_sets/blood_types/rh_factor.html
hope those help.
I'm not sure abuot the RH factor, thats def. a good question to ask the doc. About getting preggo, if you were to get preggo you could test 14 days after Ovulation with a hpt. So as long as you know when you ovulate, have sex on those days and test 14 days later you've got a chance!! Good luck to you:)