Has any moms taken sulfameth while breastfeeding? I went to the er this morning with severe…

Has any moms taken sulfameth while breastfeeding? I went to the er this morning with severe abdominal pain, I found out apparently I have a really bad uti and my white cells are really high. I'm allergic to amoxicillan and they didn't wanna give me Cipro so prescribed bactrim whose generic I take is sulfameth. I have a 2 week old and the pharmacy guide said don't give to babies under two months and since it excretes in breastmilk I'm nervous. The ER doctor said to nurse than take it than drink lots of water before I nurse again. The pharmacist said he wouldn't feel comfortable if it was his wife, I called his pediatricians office and the on-call Dr said he should be OK. I think I'd feel comfortable if I knew someone else took it and had no issues. I feel horrible because I don't wanna chance anything but I also don't wanna stop breastfeeding. I'd pump but it takes me an hour to get two ounces. Any help I would really appreciate!