Helpppppp

Why is it that it’s hard for me to get pregnant bye pre cum around my ovulation . I don’t let my boyfriend get to the point where he needs to nut I just want to get pregnant by his pre cum.... I even tried having unprotected sex on my ovulation day bye his pre cum getting me pregnant but it still didn’t work. Why is it so hard for me to get pregnant by it!?? I thought pre cum was higher then semen . Got my period and I’m mad . Symptoms has was sore breasts, bloated gassy stomach , fatigue , mood swings. White discharge, headaches