Why am I late?

Hey so in December I have my period early and when it was finished I had sex and the condom broke so the same day I got plan b and maybe a week or two I was bleeding again for 4 days and that’s the length of how my period is . I searched this up and it said plan b cause bleeding, now in Tuesday Jan 8th at night I felt sometype of discomfort when I finish peeing and I searched it up and it said UTI, but my period was supposed to come this week I’m 5 days late. Is it the UTI that caused it to be late or the plan b I took? Please help

I recently went to the hospital and they made me take a pregnancy test and it’s negative

Why am I late