Prego scare!

Okaaayy... so i need y’alls help. My boyfriend and I have been having sex for about a month now. Well the 3rd time we had sex we noticed some cum rode up the condom (unsure if any got out)... i should have gotten my period or should be getting it very soon but haven’t. I got nervous yesterday and took a pregnancy test which came back negative but it was only $1 so I don’t know how reliable it is. Should i take another one? Or wait until Friday?