To begin with there is no absolutely 'safe period' during the period cycle if you mean safety from conception. This is especially true for those with irregular cycles like yours. The maximum chance of conception usually occurs 14 days before the next period. That’s the day when ovulation takes place (an egg is released in the woman’s body). If a woman has unprotected sex with a man at that time, she can get pregnant. If you do not know for sure when you will have your next period, it is not possible to calculate when ovulation has occurred. So, you will have to be on a contraceptive pill or your partner will need to use a condom every time you have sex if you want to avoid getting pregnant. Bleeding twice a month is not always a healthy sign. You may want to consult a gynaecologist to discuss the frequency and irregularity of your periods as well as get a prescription for a contraceptive pill.