Birth control & prenatal vitamins

I have a question & I hope you guys can help me.

I want to be pregnant but I have had no luck yet it's been about 9 or 10 months now of me trying but no luck.

Also I have been taking my prenatal vitamins everyday for 2 months straight. I haven't had my period in over 3 months but my period has always been this way... so I get it one month n then it skips a month or a couple of months then it comes again.

So now my doctor gave me birth control to regulate my period. I'm still taking my prenatal vitamins, today will be my first time taking my birth control pill if it's okay to mix it with my prenatal vitamins.

Can someone tell me what to do or not to do? Is it okay or not?

Thank you in advance :)