Negative results 6weeks since Period

Can anyone help put light on this?
We have been TTC for 5months.
I average 4.7-5 weeks between periods. This time I am 6weeks and I have no body changes at all to tell me  I'll be getting it soon.
No sensitive nipples.. I feel I have bloating. Sometimes I can't stop wanting food.
I have done 4 digital early response tests and all negative.
Is it possible to miss a period and not be pregnant?