Hi;
welcome to HealthcareMagic
The normal cycle of periods is between 21-35 days any thing above or below is not normal.
Irregular periods can be due to
hormonal imbalance but since you are sexually active with irregular always do protected sex & be alert if you miss your period so that you don't get pregnant if you don't want to.As for come /finish is it orgasm you are talking about or any other problem please write in detail to help you better.
Thanks