Uti??

Heather
I'm 6 weeks today. I have had on and off back pain last 3 days. But today I noticed my pee smelled really strong. It had earlier in week bc I had been on amoxicillin but that was done Monday.
My first u/s is Friday morning. I'm trying to wait and have them check for bladder infection or uti.  But it burns and worse when I pee. Back still hurts. 
Anyone else have uti this early on? If so what were you able to take to treat it ? I always end up w yeast infections after taking antibiotics :/