So, last month was a rough one. I had a uti that turned into a kidney infection. I also had a yeast infection from the antibiotics that were supposed to get rid of the uti. I went to the hospital for the kidney infection. They put me on stronger antibiotics. I took a pregnancy test 3 days before this and it was negative. I ended up bleeding the day I went into the hospital but after they gave me iv and antibiotics. It was a light period. I never filled up a complete pad and I didn't have clots. Can antibiotics make your period lighter? I always thought it did the opposite.