Advice?

Madison • I`m not trying to get pregnant, not intill I`m married, so this is just for my period.
Hi, I'm trying to talk my mother into birth control because I have very irregular cycles, but when she wa discussing it before, it didn't help her a bit with her irregular period. Should I just go on and ask for it? And how should I ask? 
Also, what kind works the best ( in your opinion).