Newbie Help!

I went to the clinic two days ago to grab my first ever set of birth control pills but I have NOT started taking them yet.

I’m ovulating this week and I’m still not on my birth control.. but I had unprotected sex today, he did not ejaculate in me.

I’m on the first day of fertile week, chances are low but I still took Plan B in 24 hours since unprotected sex as precaution.

So.. I just took Plan B and I am now planning to start my birth control pills. Should I wait a few more days to start or my next period? Or am I okay to start it as soon as I can? (e.g., an hour after taking Plan b)

Thank you so much for your help!