Is m/c inevitable if i have BV, UTI , and Yeast infection at 19 weeks???

I am 19 weeks pregnant and have had a Urinary tract infection since my 13th week. Doctors and I thought it went away, but then the symptomes cam back just 2 weeks later. They gave me Macrobid again, and it was confirmed that the meds did not work at all and my leukocyte levels were sky-high when tested again. I am now on Sulfur.... sorry cant remember how to spell it all. I was also given a Bacterial Vaginosis gel for 5 days just in case i have BV. I am taking both at the same time. I now have a yeast infection it seems. I am having lots of cottage cheese discharge accompanied by some burning. The doctor tells me that the yeast infection is a sign that the antibiotics are now working. Is having all this bacteria (not to mention antibiotics) safe for the baby??? I have had 3 miscarriages before and one was at 16 weeks. Should i be concerned?