My period

I'm about to be 16 and my mom wants me to get on birthcontrol and my period is irregular sometimes it'll come on time or maybe 2 months later but I don't bleed heavy and it doesn't last for long maybe 4-6 days and not really heavy with such bad cramps to where I'm throwing up with dieriah and bleeding and all three of those things it's just ugly for two days but not every time I get my period that happens but what should I do?