Pregnancy chances? (Anal mentioned please don't judge Dx )

So my boyfriend and I were messing around and whatnot and he wanted to do Anal but he slipped out and brushed my vagina. I didn't see precum and I'm on the pill. But I've only been on the pill for a few weeks.

Can I get pregnant from a light brushing if there's no precum?

I feel sick but I also have anxiety and I don't want my mom to find out 😭😭😭