My very regular 29 day cycle is late by 3 days. Last week I had a surprise yeast infx and now a kidney infx. I was prescribed Macrobid and pyridium. Can either of these medications cause a false negative pregnancy test result? I have two children and feel pregnant but I m kinda hoping this is a fluke.
Hello, Macro bid and pygidium are not known to affect pregnancy tests.  The most common cause of a false negative would be that it is still too early, for example, if you ovulated later than expected and the pregnancy hormone is still too low for the pregnancy test to detect.  I would suggest rechecking again in 1 week if you still haven't had your period, and if it is still negative, that should confirm that you are not pregnant (assuming you haven't continued to have unprotected sex). Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor.