17 weeks pregnant with a really bad UTI

I woke up the morning of my appointment this past Thursday to pain when I pee. Luckily my appointment was first thing that morning so I told my doctor when I got there. He took a urine sample and told me they’d call me with results. They never called me. The office is closed today as it’s Saturday. Yesterday I felt fine and thought it had passed on its own from all the fluids I’d been drinking. Today it’s unbearable. It hurts to pee, as soon as I pee I still feel like my bladder is painfully full and there’s small amounts of blood when I wipe. I absolutely cannot afford $2000 to go to the ER. What can I do to hold me off until my doctors office opens on Monday so I can get a prescription? Is this bad enough that I should just take on the debt and go to the hospital? The pain is awful. This is my 2nd UTI with this pregnancy and the last wasn’t nearly this bad.