I have a question here. Is it safe if I have unprotected sex with my girl and ejaculate in her on safe days of her menstrual cycle?

You decide. There are no absolute "safe days".Pregnancy from unprotected sex has been documented on any day of a woman's cycle, including during menses.What you describe is affectionately known as Vatican roulette.If you are not ready for pregnancy, use appropriate preventive measures, not just hoping it will work.