please I need advice!

I am due for AF Wednesday 
However for the past 6 days I've been taking pregnancy test and one day its positive the next negative for 6 days in a row  the lines on my test are faint but visible and light pink but today I got a negative and yesterday positive day before that negative and before that positive 
My Af is due in 2 days if I were to be positive wouldn't it be more consistant? It should've have been positive today as well no?