When Is The Most Fertile Period During Menstrual Cycle?

I went to the doctor for examination...because me and my fiance have been struggling to have a baby and the doctor said one of my tubes is blocked bt the other one is okay...and he prescribed Fertomid and pregnacare conception...and advised me to take fertomid 100mg on day 2-6 of my cicle and so i want to know when will i ovulate and when is the best time to try for twins im desperate for them.my cycle is 28-30..plz help PAM