 [ Symptoms ] i was born with bilateral pars defect and have spondylolysis can i fix this or help with the pain [ Disease ] hi masturbating may lesion your chances as you say will expel his sperm form your vagina but in the heat of love making these things do happen around day 143 should be ovulation day giver or take a day so you need to be having unprotected sex around day 9 this gives his sperm a chance to be in your womb waiting for the egg sperm can live for up to 10 days max in the womb and sperm takes 3 days to reach your womb so day 1 first day of your period day 9 unprotected sex day not to much sex or masturbating him before that day and just lay on your back with your legs up after sex they say that last bit helps but do relax its best that way give it a chance and it will happen good luck