I'm not sure I understand your question. While pregnant, most women do not menstruate.
Masturbation, and particularly the female orgasm consist of contractions of the uterus. This could increase the menstruation discharge, as it the result of the womb removing the excess blood and tissue when preparing for the pregnancy while ovulating.
If you're trying to conceive, some doctors recommend that you not cause these contractions, but others recommend the exact opposite, so it is important you get advice from someone who knows you.
