faint positive then a negitive

I had 2 faint positive test then a week later 2 negative ones. I haven't had any bleeding though. am I pregnant?

test 1 - standard clearblue(pos)

test 2 - 6 days sooner first response (pos)

test 3 - 6 days sooner first response (neg)

test 4 - digital clearblue (not pregnant)