Late but negative tests :(

So I'm officially five days late. I took a One Step strip test after two days late and negative. So I took another today and also a Clear Blue test today and still negative. No symptoms except fatigue and a little constipation. I dunno what's going on. I did kind of abruptly quick taking anti depressants a week ago but it was a really low dosage and I've been fine without it. I've also gained some weight in the past few months. Went from 226 lbs to 236 lbs