Hi everyone. I took cheap pregnancy tests for a couple of days now and the last 3 were positive but this morning i too

k a early detection pregnancy test and it came back negative im so confused as to why it will be like that. Can it be a chemical pregnancy or are the cheap ones wrong. I used Mamma Perfect (the cheap ones) and this morning i took a Pick n Pay early detection test. Any advice would help. Im not sure how long my cycle is it is between 28 and 35 days so that means im 6 days late or 1 day late for my period but i also have endometriosis. The positive tests is a bit darker in person than on camera and the second last (cheap srip) is positive just cant see it on camera