Clomid causing late period?

I did round 1 of clomid and I'm always on time with my period and well another app I use to keep track of my period states I should have gotten it on Friday and that app is always on point I've been using it for over 8 months and never wrong in when I should start, and I haven't gotten it yet, and I did 3 pregnancy test and all negative. Has anybody had this probably wurh clomid?, being late in your period, or actually my same situation with negative test but turns out your pregnant? Trying very hard to not get my hopes up right now. This is not fair, wanting something so bad and being blind sided with these clomid side effects.