my body so weird

I don't know how to explain this but my body feel such a weird way. 
Me and my boyfriend had sex around 1.5 years from now (unprotected, nothing goes worst). Last month November 28 he reached his climax in my back side and nothing really happened as well
Around 3 days from now i felt so weird, my body wants to go pee so bad. I have take uTI medicine, and now i feel hungry more than i should. I mean, I eat more than i normally do. 
My period should happened on 18. It didn't happen yet. Only some urine with blood come out together. 
I check 3-4 pregnancy test. There is just 1 line. Any advice? Thank you.