water infection whilst pregnant.

Ladies I'm currently 3 days in on water infection. Been doctors this morning and they have given me antibiotics, she said she could tell by my wee sample without even testing just how bad it was. I'm prone to them in pregnancy. But when I wiped it was a bit pinky courled, & she said there was a lot of blood in my urine. She said if I start bleeding then to go back so she can rule out etopic pregnancy which I explained I've had early scan at 6 weeks and all is fine, but can't help but worry that something is wrong if there's so much blood in urine, hardly anything when I wipe, doctor said nothing to worry about but how can I not worry.  Is she right or should I be more worried? Currently 8+5 days xx