Cramps for 2 days without bleeding? HELP?

Yesterday and today I have be having menstrual cramps but no bleeding. My term isnt supposed to start until 5 days but it is irregular so it might not come this month. I am quick starting YAZ birth control on Sunday to support with the irregular period. It might not come for another month so that is what the birth control is for. Im not sexually live. Anyway, why could I be having cramps in need bleeding. Also have you taken YAZ. Could you recount me your experience on this birth control and about the early start method of taking birth control. My cycle is already messed up so it doesnt matter when I start birth control.
Answers:

36c and im merely 13 omg thats sick what do i do !!?

I have be taking BC for 8 years now to regulate period...they would only come approaching 2 or 3 times a year!

Wait an entire month for you body to get used to the BC and as long as you rob the pills on time, your body should regulate itself sooner.

I other mess up my pills and would get cramps precipitate or late near bleeding or no bleeding...our bodies are wierd, its ok!