What Are The Chances Of Pregnancy After Unprotected Sex?

Hi.i had unprotected sex during my ovulation but we used the withdrawal method,that time i noticed a lot of wet fluids.is there a chance i get pregnant because he was sure nothing he puts inside.today is the schedule of my period but nothing,i feel sore of my nipple and a bit of cramping especially in my abdomen.what does it means i had miscarriage 8 mos ago.pls help....thank you