Hi, welcome to the forum!

If you started your pill on Sunday you should've used backup for seven days (until the next sunday). Since you didn't start it within a few days of the start of your period, you weren't protected right away. When did you have sex?

No one can know the exact chances of you getting pregnant before those seven days. You can only take a test to find out.

I had sex next tuesday. One week after I started my period and I had taken 2 pills already

Then you weren't protected. I'd just get a home pregnancy test.

My doc told me I had to use back up for the first whole month

I don't know why some doctors say that, because all of the packages and drug companies and planned parenthood doctors say a week.

Not that I'm doubting you ruwired2, I'm just saying that there is a definite discrepancy.

I'm tending to agree with Georgia since that's what all of my doctors and the products themselves have told me.

I would think a lot of drug companies would get sued if you actually had to wait a month, because all the packaging says a week and girls would be getting pregnant all over.