Hi I'm due my period on Friday. I have had sore boobs, feeling nauseous, tired and crampy. I've also had white sticky cm whereas I'm normally dry post ovulation sorry if tmi. Yesterday I took two pregnancy tests one first response and the other a cheap shop brand one. Both were positive. This morning I've done two first response tests and both negative. Feeling really deflated at the moment. Is this a chemical do you think? I tested with fmu