4 days late

Is it normal to be 4 days late on your period. I currently have a Uti and I’ve been on it for a bout a week now. (Weirdly I haven’t had a uti in two years). Can a uti delay your cycle? When I went to the emergency room and they did a urinalysis for my uti they tested for pregnancy as well and it cake back negative. What could be the problem?