How likely is it to get pregnant on your period

I’m 7 weeks pp. they told me to use condoms until I’ve been on the pill for two weeks. On Tuesday it would be two weeks . I’m at the end of my period. I’ve been on it for 4-5 days so barely even bleeding. We had sex this morning and the condom broke and he came in me and we didn’t see until after. Now we’re both scared. Can I get pregnant on my period and being on the pill for 12 days

And when would a pregnancy test be accurate ? 2 weeks from now ?