When is the safe period to have sex between menstrual cycles?

Guess: Is hard to gage . The best time is 1-2 days are finished your period and before your period. Sperm may stay viable in the fallopian tube for up to 5-7 days after intercourse. Ovulation is about 10-14 day from your menses. Your are close to ovulation when your vag secretion are more fluid, elastic, you feel more in the mood & oral temperature tends to go up (you will need to do temp diary in am.

Safe?: I do agree with the previous advice as a loose strategy, but emphasize this is not guaranteed if you seriously mean to avoid any chance of pregnancy. This gameplan is traditionally called the 'rhythm method' and clinical experience shows it's around 70% effective. Consider your options.