Am I really prego

So can anything trigger a bfp? I went to the doc 4 days prior to my many bfp and he could t see any sign of pregnancy on vaginal ultrasound. So now I’m noticing a fishy smell when I urinate I do get BV from time to time. I can’t get in the doc till May when I’m 9 weeks. So I guess my question is can a uti trigger a bfp?