Need help!!!

💞Kimberly💞 • Im 28. I`m a mother of two wonderful little boys. Then i have three step kids. One boy and two girls. Im happily taken!
So I've been having really bad pains in my left side, I've went to the hospital, and doctor and they don't know what's wrong. The found blood in my urine. My period is late they have also did a pregnancy test and blood test both said I wasn't pregnant. So I don't know what to do!?!