Pregnancy testing

I had my daughter almost 6 weeks ago and had sex around week 4 we used a condom and it broke because of course the universe just wants me to get pregnant again right away lol. I took plan b 6 days after cause i got in a car accident and was unconsious for a couple days and wasnt really thinking about it.I took a pregnancy test today and it was negative but I'm just wondering if I took it too early how soon after should I take one to get an accurate and reliable result.