Diagnosed with UTI, but now have black stool?

Yesterday I went to see my doctor after having blood in my urine (noticed when I wiped) and after a urine sample was taken my doctor told me that I have a UTI (doctor said I had pus and blood in my urine) and gave me a script for antibiotics to take for 7 days. This morning I have been feeling really nauseas and when I went for a number 2, I noticed that my stool was black and tarry looking like.

I have no idea why as I haven't eaten anything that could turn it into black and was wondering whether I should go back to my doctor and whether the black stool is anything to worry about? I'm taking prenatal vitamins and have been taking them for 2 months and haven't noticed my stool being black before, so unsure whether this could be the cause?

Thank you.

[CalGal]

Check with your pharmacist to see if the meds you're taking could cause the presence of a black stool. If you're not eating foods that could cause a black stool, or if you're not talking meds or using pepto-bismol, then call you doc and tell him what's going on.