Positive and negative tests

I have had 3 positive tests but the pregmate keeps showing negative. Was due to start cycle yesterday. Two days ago had a negative with FMU then a vvvfl on pregmate and a positive clear blue both within time frame. Yesterday had a positive FRER. Still showing negative on every pregmate I’ve taken since. I’m never late, usually have a short luteal phase and would have started by Sat-Mon instead of Wed like it should be. So confused 😩

Has anyone else had issues with pregmate tests?