BFP first response but not other hpts?

Victoria • Rainbow baby due 9th oct 2019. Third time lucky 💗

has anyone else had countless negatives from clearblue, boots and viola but reveived a BFP from a first response test a day later? AF is due tomorrow and I have lots of symptoms including veins over my boobs and abdomen but so far I've done probably 8 tests and theyve ALL been negative! :(