Whether accidental or deliberate, both morally and legally the right to continue with the pregnancy or not belongs to the mother. If the pregnancy is accidental it is best to terminate it since there is no conscious thought and planning that has gone into it. Bringing a child into the world should be a conscious process. An unconscious movement only tends to draw forces of tamas and darkness. But if the mother wants to keep the pregnancy then her decision has to be accepted and respected.
There is a whole science indicated by stories about continuing with pregnancies that were the result of unconscious movements or the result of an act of pleasure rather than the wish to have a child. Ravana was one such example. The act is the same but the motive and attitude makes a big difference in the actual result.
Affectionately,
Alok Da
