Will starting birth control now stop my period?

Emily

I have to get on birth control again because I haven't been on it in a few years. I still have some pills from the last time I had it. My period is late again (it's never regular) and I'm going in vacation with my boyfriend on the first. I was wondering if I started taking the birth control in a few days until we get home if that would stop my period from coming until I stop or if it's already too late. Also unrelated but has anyone gotten the pill without insurance? I'm on my dads insurance and I'm too scared of him finding out but I want to go to PP to get the pill again and I want to know how much I'm looking at there.