firtility is usually 12 to 14 days before your period. if you are trying to concieve start taking folic acid asap, quit drinking and smoking. its give you a higher chance of conception and helps your baby with a strong start to life.
google some fertility calculators and put in your information - it'll give you a good idea of when you ovulated, though it's not to be taken as a doctors advice. take a pregnancy test if you are late or miss your period.