false positive/false negative?

driving myself absolutely crazy right now so I'm on currently on day 43 of my cycle and 15 days late for my period.

last Friday at 19:00 i took a pink dye test which had a vvf line couldn't wait so used a clearblue digital on Saturday morning 7am which said not pregnant.

on Monday I couldn't wait any longer so took another digital at around 19:00 which came back positive.

went to see the doctor on Tuesday who said yes all sounds positive to me & referred me to the midwife.

on Wednesday morning at 6:30 took another digital & this said not pregnant!!

so right now I have no idea what to think?!

anyone got any insight?