Pregnant or not


I have a rough idea of when my period is due but they've been all over the place recently. I've been tracking my periods for months. Anyway I'm roughly 2 days late on period. I've taken a few tests today and both had faint lines but got some this afternoon and negative! It's killing me waiting. I feel so poorly recently. I've had period pains loads but obviously no period. When should I test again?