So I have taken several pregnancy tests over the past week and all have come back positive and seemed to be getting a smidge darker, also had a cb digi come back pregnant 1-2 weeks, then took one the next day very late at night I must admit and came back not pregnant, and since then I have taken some clearblue normal tests and the lines have come back very faint, af was due yesterday and still no sign of her today.. very confused can someone help I am quite worried this is a chemical?