Lover Dear Lover, You are not necessarily wrong, but Alice thinks your girlfriend's worry is not without reason.
Some methods are more effective tha n others.
In your girlfriend's case, the birth control pill's failure rate, or possibility of causing accidental pregnancy, is very small, and depends on the type of pill used and schedule of use. If your girlfriend has not been taking the Pill consistently and correctly, then her chances of becoming pregnant are much higher. Talk with her to determine why she feels the way she does, and then see if both of you can come up with a resolution to help her stop worrying. She may choose to use a condom because in this way, she can see your collected ejaculate and know that it is not inside her, and this may be reassuring for her to know. Basically, Alice suggests that you and your girlfriend discuss your contraceptive options and choices with a health care provider, if you haven't already, and then decide which one is right for both of you.