Intense cramp

Cl

My last period started around 9/12/18 not on any birth control as ttc, for the past 2/3 week I’ve been having cramps not constant but they come and go lasting for around 30 seconds - 1 minute this has woken me up a few times it’s quite intense for the short time it lasts. I went to the out of hours doctor just over a week ago and the test they done was negative. Could I be pregnant still? As I would be 6 weeks